I NEVER MIXED COMPRESSED AIR WITH THE REFRIGERANT! IT WAS EMPTY FROM A LARGE CONDENSER LEAK! Some of you want to argue, that what I showed was unsafe. Please tell me how an empty system, filled with compressed air, is a safety concern. I'm not asking about the supposed contamination. I am asking about the safety side of this procedure. I certainly do not endorse unsafe practices. Here is something I found on a Google search from some engineer forum... HFC-134a is not flammable in air at temperatures up to 100 deg. C (212 deg. F) at atmospheric pressure. However, mixtures of HFC-134a with high concentrations of air at elevated pressure and/or temperature can become combustible in the presence of an ignition source. HFC-134a can also become combustible in an oxygen enriched environment (oxygen concentrations greater than that in air). Whether a mixture containing HFC-134a and air, or HFC-134a in an oxygen enriched atmosphere become combustible depends on the inter-relationship of 1) the temperature 2) the pressure, and 3) the proportion of oxygen in the mixture. In general, HFC-134a should not be allowed to exist with air above atmospheric pressure or at high temperatures; or in an oxygen enriched environment. For example HFC-134a should NOT be mixed with air under pressure for leak testing or other purposes.
ScannerDanner some one touch a raw nerve. I also have seen in a Mazda service manual a caution not to use compressed air due to possible ignition of gasses. In Australia we use inert nitrogen to test the system's compressor function, but do as you do bro. The system should also be flushed with compressed air and solvent. Also I found many videos demonstrating how the charging system of a vehicle works, your last explanation was not clear in your last video due to language difference such as "control wire". Nevertheless the control wire switches the solenoid and the main power wire from the battery goes to the B+ post. Thanks for clearing that up bro.
If you caused an unsafe condition by using compressed air, then I'm going to buy a lottery ticket tonight and WIN, and then I'll take you, and ALL the subscribers of this channel on a cruise with me next week. :) In other words, we've got a better chance of being struck by lighting ... TWICE ... and winning the MA state lottery ... in the same hour.
The Google search quote is straight out of the Material Data Safety Sheet (MSDS) for Dupont Isceon M099, i.e. HFC-134a. The take away from that would be to not expose the pressurized, hot air/HFC-134a mixture to a flame or, secondly, use a compressed bottle of 100% oxygen to pressurize a refrigerant system with entrained HFC-134a. So Paul is perfectly fine to utilize shop air. Great video.
Nope, R134A is not combustible in the atmosphere , so putting air in there works the same way, the negative point by doing this is that you are introducing water vapor in the a/c system but he explained that anyway there was a leak therefore air and humidity were in already.
I had a similar vacuum leak issue on a 2003 Envoy that was dead empty, tried the compressed air at about 70 psi and found the leak in 5 seconds, litteraly hissing out the condenser, no soapy water needed. This weekend will replace the condenser . Great tip and videos as always. Thank You!
Paul, I trained on Automotive AC at the GM training center in Tarrytown NY many years ago. Over the years as a Chevrolet Tech I worked on many different systems and always took the advice of the instructors. They had developed many different techniques that weren't in the book and still aren't. Please continue with your advice no matter what the criticisms are...
What about you share those not in the book? This is a good test but I feel like it is very hard to spot small leaks. In my case I was losing about 10 psi @100 test pressure every 5 minutes. This is a very small leak, cannot hear it and would not be detected easily. My next step is to inject dye and see where it is.
@@scientist100 dye injection should've been your first step. I find leaks in 10 minutes or less. Don't have time to spend 2-3 hours chasing a leak at high volume shops
@@harryazzole7814 only if you can see it. Anything after the firewall requires time that the dye test won't show. I can hear a large leak right away with ease, dye would take longer time to inject and wait for it to show.
mr Florida guy may I ask u a question.. gmc truck 2015 yukon expansion valve is leaking replaced the seals on expansion and the hoses twice and cleaned surfaces.. still leaking any advice will help..it's driving me insane
Most of your tutorials are 100% money makers. I have used your tutorials for research, diagnostics and repairs. All without issues. Got nothing but great appreciation. Thanks man!
Both of your A/C troubleshooting videos using compressed air, with explanations of the various systems, is outstanding Paul!! You have made this complicated system a workable one for us DIYers, and plenty of thanks to your fine son in helping his dad too!!!
Man first off just want to say thank you for your content and the information you share. I was able to find the leak on my wife’s 2011 Chevy traverse and replace the parts that needed to be replaced. The local shop wanted an arm and a leg for the work I was able to get done at the fraction of the cost by watching your videos and investing in a set of gauges and a vacuum pump. Thanks to y’all my wife’s SUV is ready for another hot summer in the high desert of CA.
I will say your videos on ac troubleshooting and repair are the best anywhere. I’ve been quoted $3500 to start on ac fix. With your help I’m under $1000 with rear evaporator core, compressor, r-134, and vacuum pump and manifold gauge. Thank you for videos!
Thanks for this it saved me wasting expensive refrigerant. I put the money I saved towards a small compressor instead. The stethoscope tip from another reviewer will help in hard to reach parts of the system. I cant do any physically demanding work on my car due to poor health. Your video has empowered me to tackle this job myself. I will gain that sense of achievement from doing it myself. Thanks.
Love this video! Pulled my system apart yesterday, removed and flushed out all the lines and added a new compressor, condenser, expansion valves, etc. Buttoned it up today and pulled a vacuum, but it wouldn't hold very long. I was weighing my options on how to find the leak (including pulling everything apart again), found this video, pressurized system to 50 lbs, and voila! One of the dryer lines had a slice in the new o-ring and the connection was bubbling. Swapped out that o-ring, and now it holds a vacuum. Thanks so much for posting.
.......Nice to hear someone speaking clear english while doing a video. Some of these tech videos move so slow relaying pertinent information , that I can't even get through the first thirty seconds of the video. Thanks for an informative production.
It is me again Paul. This is the second video I have watched and I like your common-sense method of diagnosing leaks. I am 71 but interested now in learning how to diagnose and repair vehicle AC systems. Gotta keep my mind plugged in. Thank you for taking the time to produce these free videos. May God richly Bless all that you do and your Family as well.
Agree with you good common sense information that a guy can do at home with the stuff he has I also know people that have used compressed air to find leaks they never caught on fire or exploded and when finished they had cold air and no customer complaints Thanks Scanner Danner
Have been doing A/C for 42 years .I have been using compressed air with moisture filters , air used to paint cars, Must use moisture free ai,r I have seen air hose blow out a ounce or 2 of water that would be impossible to vacuum out of the system .1 system is empty or. Recover system .2 add 150 psi paint air.3 I now use a Robinair ultra sonic leak finder , it hears leaks finds leaks to 1/2 ounce per year. then use soap and water to show customer the leak used soap and water before I had the Robinair ultra sonic. I do over 1000 cars a year.
It's funny how some people are such experts on Y-Tube. Experience means nothing. Better not undo a fuel line, two drops of fuel might explode into a raging inferno. I have been repairing A/C systems for over 40 years and I have never had a problem with using Nitrogen, compressed air, electronic or refrigerant (R-12 days) while testing for leaks. In real life repair you do what you have to do within the limits of your knowledge and experience. As far as moisture goes, on the assembly line they pump em down for 10 seconds and then fill them. I guess that's why they install a drier. A tip for soap, Dawn liquid dish washing soap seems to make the most bubbles. Well done, Paul in my opinion.
You are correct if it working on a car that's been around a long time I would do two things change the expansion tube or clean it change the filter drier accumulator because of a bag of dust in the dryer degrades and can break I've seen that and you got one hell of a son of a b**** in mess
I was ready to take this system I just built to the shop and pay$$$! New compressor, condenser, accumulator, and orings all around. Yet, I couldn't maintain any vacuum. Your simple and straight forward approach - I found my leak. You are an obvious genius~! Thanks...
My main job is mobile car AirCon. Over here people are under the impression that car AC systems just need ‘ topping up ‘ every couple of years. As if the refrigerant is a consumable substance... Anyway, this video is brilliant, and is exactly what I was looking for a couple years ago when starting out. Really thorough and full of facts! The only thing I do differently is that I use oxygen free nitrogen to pressure test. But can’t see a huge problem with using compressed air as long as the system is thoroughly vac’d afterward. Bang on mate.
Great video. Your comments are right on. Most show a simple video they copied for elsewhere and don't really understand it. You actually thought this whole thing through. Smartest video so far. Thank you!!
Scotty also pumps air into an empty system. He has a very sensative listening device with a long wand. He can HEAR the slightest hisss of leaking air thru his headphones. Anyone who took the time to watch his video would know that. Nobody knows everything. There are new tricks to learn every day. His new method even finds leaks behind the dash.
Years ago I worked for IBM and I did an upgrade to a 3715 printer. The upgrade allowed the printer to print faster and an easier to install ribbon. To make the printer faster all you had to do was move a jumper. I took my time doing the upgrade because I felt bad for the customer because if they knew they could have done the upgrade on their own and not paid all that money for me to do it they might have been upset. My point being some of these guys don't like you coming along with a test light or some compressed air and using sound logic to figure out a problem. They want to come in with their bells and whistles and magic and behind a curtain like the Wizard of Oz fix the problem. Knowledge is power and you are helping people just like you help your neighbor when he needs it. You can relate to this. I fixed a Chevy Impala once that was having trouble getting it started. I told him it was his carb and he needed it rebuilt. He asked me if I could get it running so he could get home and his brother in law told me not to do it for free so I told him I'd get it running for 25 bucks he agreed. I went out and had him crank the engine while I tapped the carb to unstick the float and it started. He said 25 bucks was a lot of money for just tapping his carb so I told him okay 5 bucks to tap the carb and 20 bucks to know where to tap it. Great vid Brother. Your logic is sound and sometimes you have to read the directions or in this case listen as you qualify the condition of the AC system. GBWY
Compressed air to test ac system leaks is definitely going into my arsenal of diagnostic methods...Any nay-Sayers are apparently oblivious to the fact that once repaired, the system will undergo vacuum to remove air moisture before recharging...
BTW, I would recommend using something called Seek-a-Leak which is designed to find leaks on tires, similar to soapy water but better results...Works great for leak testing tires as well as any pressurized tank, hoses, fittings, etc...Also, would like to take this opportunity to thank you for your great book, one of my best investments and diagnostic tools ever!...
But wait... I get if it's a leak and you're trying to find it. The filter drier is already gone as once the refrigerant leaks out, the air can and does come in. It won't hurt to use compressed air at all in this case. But what about leak/pressure testing on a newly repaired system? Wouldn't you want to avoid exposing the newly replaced filter drier to moisture and use nitrogen instead at that point?
ONLY if you want to change your dryer and expansion valve. ANY moisture added to the vacuum system instantly ruins an AC Dryer. NITROGEN - NOT SHOP AIR is a MUST or vacuum and use freon. He literally just ruined that cars AC system- sure, it will work in the short term, but never work correctly again until the dryer is replaced.
POE oil absorbs moisture that will not be removed just by pulling a vacuum, but I suppose that's not a problem if there was a big leak some time ago and all the oil has to be changed anyways...
Thank you for this video. Been fighting a leak on a completely new replaced system on my 86 mustang. Wouldn't hold a vaccum so I could add refrigerant. This let me find the leak in the brand new pressure switch. Replace switch, now it holds vacuum.
An old timer told me that kid's bubble liquid works very well for finding leaks. Ever since then I've mixed 50% bubble leak detector with kid's bubble liquid. Works extremely well for small leaks.
To make adding or maintaining pressure easier, get yourself a high side quick connect and put an air fitting on it. That way you can run air to it all the time and not have to go back and add any if you bleed off.
Hello, I am trying to find a leak in my 1999 F230 super duty... can you tell me what fittings I need to buy to fill the AC system with air using guages..(that I will purchase too)
Go to an auto parts store and get a high side coupler and screw in an air fitting of your choice. The threads arent a perfect match but put some teflon tape on it and it will seal up just fine.
Wonder if anyone actually makes an adapter for this purpose, or is it considered too "taboo" to sell, like an extension cord with two male ends- Strictly a DIY item I guess.
Save your trigger fingers (unless you're into body building) and try using a pump lawn sprayer (mine from HF). Works great for flat repairs too! The long tube gets into tight spaces as well. I fill it maybe once a month. After 45 years the hands get a little painful squeezing triggers.
I had a compressor front shaft fail in my 86 mustang. That was fun to find! It held a vacuum all day long, but could not hold the refrigerant pressure.
I came looking on how to introduce compress air to my impala ac and this video did not disappoint. I didn't even type Impala and it was the first thing that popped up. Awesome work guys
I would also also like to add. The cheapo trigger pull freon gauage valves that you get on like an AC pro has the same female threads as a air compressor male connector
I just used this method and had a heck of a time finding the leak, turns out BOTH service ports were leaking. I have two dryer filters on my air line so I wasn't worried about moisture. I Vacuumed the system down and it held! This was on a 2000 Tahoe. Thanks for the video!
Did you just listen for the leaks there instead? Or just release the pressure from the gauges and check for pressure coming back up without opening the valves?
Hello my friend Paul I always wanted to see how someone can check ac leaks with compressed air. Absolutely a awesome video Paul. Your son is quite some camera man. God Bless the whole Danner family
Thumbs up,right off the bat; i do the same thing; for over 30 years. The only thing --remaining-- is under the dash,inside the car; and for that you need at least a small charge of "freon" and the electronic "sniffer".
good video..this is the time that an ultrasonic leak detector is invaluable..it hears compressed gases coming through small holes that are out of the bandwidth of your ears....it can hear compressor shaft seal leaks and evap cores leaking. they're not perfect but gives one another tool in your diagnostic kit ...mines has pulled my butt out of many problems..look in to it..you won't be sorry...
Update! Just did this on a international 4300 truck,,, found the problem in about 2 minutes,,, we get quite a few small leaks in the big truck World at our shop ,, thanks again for the info!
I have deep feelings for and about this one. It showed how to tell the compressor still works !!! when I'm and my beloved is coming from like situation of emptied system dry from leak ...right? Been left without working it sporadically to keep it I'm shape. But mostly it determines compressor does function and I haven't hurt it.
Just a thought. You might consider dye along with the compressed air and increase the pressure to 250 once equalized. That would find ALL the leaks without starting the system for more than five seconds.
That comment you made about compressed air is what I've always thought. In fact I made a little piece to connect to my compressor and my manifold gauges. I fill my system up to about 100 PSI every time I do an AC repair just to check it and I've always thought that the vacuum process would eliminate any moisture that the compressed air may cause...... AND I've never had a problem in the decades I've been repairing cars.......
I have a small flask of ultra pure nitrogen that I like to use for testing. A bonus is that it's a very quiet process and can often hear leaks. I use a UV torch to search for leaks in a dark as possible workshop. The leak will fluoresce under UV lighting.
I can't believe I never thought of using compressed air and soapy water to find a A/C leak. Thanks for the video. I do remember the abominable snowman cartoon. When I got older, I realized they were doing a takeoff of Steinbeck's "Of Mice & Men" - George & Lenny.
Awesome video! I was trying to figure out how to pressurize my system since the fill port on my gauges won't fit my air chuck, but the rubber tipped spray nozzle did the trick! put it up to 120 psi and immediately heard the leak. It is the condenser, looks like a stone hit it. I need to put a screen in front of this thing!
I like this method, I have found a lot of hard to find leaks like this. I don't worry about moisture that is what vacuum is for. I do it a little different but end result is the same. Great video as always.
Good Job. I would replace the bad condenser and the dryer ,run a vacuum check and if it holds minus 30 psi for an hour.It is good to go for a recharge.
I found a leak for the first time using shop air the other day. We run some type of filter on our shop air to keep oils and waters out of it so we can paint with it. The system had zero pressure and had not been used all winter. Turns out a sticky shrader valve was leaking on the low side. I vacummed it down for an hour and left it vacuumed down one week. Since outside temps sort of got crazy cool again the following week I needed heat in this dump truck and didn't miss the air. My hope was that the engine heat and vacuum would dry out the dryer. A week later It was still holding vacuum but I vacuumed it down again for an hour. I never changed the dryer which had been replaced the season before and it was blowing 41 degrees in the vents after weighing in the specified 3.5LBS of freon. I would have never tried shop air before seeing Scanner do it. I usually use Nitrogen and soapy water but tried the air and saved my Nitrogen for another day. If it didn't work I would have reclaimed the freon and got a new dryer for it. And if that didn't work I'd go back to 2-60 air condition. LOL!
Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air.
@@dubmob151 Further to my previous comments about the dangers of using compressed air to pressure test air conditioning systems please see below quotation which was copied from a commercial Robinair vehicle a/c charging station instruction manual. QUOTE “WARNING: Do NOT use air or any gas besides N2 or N2H2 to pressurize the system. Mixtures of air and refrigerant can be combustible at elevated pressures. These mixtures are potentially dangerous and can result in fire or explosion causing personal injury and/ or property damage” UNQUOTE SD is excellent 99.9% of the time, but do not agree that it is good engineering practice to use shop air to pressure test AC systems rather than dry N2. ALL introduced moisture will have to be removed afterward. Other contaminants will almost certainly be introduced. There will be traces of oil mist in the air (from the car ac system) which may form an explosive mixture with the air and will be evacuated by a vacuum pump that can get hot. If I went to a dealer or specialist and witnessed them doing this I would be seriously unimpressed! Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air.
@@dubmob151 Further to my previous comments about the dangers of using compressed air to pressure test air conditioning systems please see below quotation which was copied from a commercial Robinair vehicle a/c charging station instruction manual. QUOTE “WARNING: Do NOT use air or any gas besides N2 or N2H2 to pressurize the system. Mixtures of air and refrigerant can be combustible at elevated pressures. These mixtures are potentially dangerous and can result in fire or explosion causing personal injury and/ or property damage” UNQUOTE SD is excellent 99.9% of the time, but do not agree that it is good engineering practice to use shop air to pressure test AC systems rather than dry N2. ALL introduced moisture will have to be removed afterward. Other contaminants will almost certainly be introduced. There will be traces of oil mist in the air (from the car ac system) which may form an explosive mixture with the air and will be evacuated by a vacuum pump that can get hot. If I went to a dealer or specialist and witnessed them doing this I would be seriously unimpressed! Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air...
Hey Paul im an Ase cert. mechanic here on Puerto Rico i do the same thing but take it o 250psi because sometimes the leak is so small that you cant find it unless you stress the place that is leaking plus the car lines are rated to 500psi+ taking in consideration the age of the hoses ,take care buddy keep on going nice channel
Thanks fro teaching safe and proper procedure. I have seen people use Nitrogen cylinders fort this diagnosis but that seems a little expensive in the long run.
Yep I'll be doing that on my 01 F350 to find the leak. Yep it will be vacuumed out and the Accumulator/drier will be changed before I put the R134A in. I don't see a problem using Air on a system that has NO refrigerant in it at all. Or starting it with air, for 30 seconds, to check the; expansion valve, pump and pressure differential, it's probably no sweat at all. In fact it's a technique I doubt would have thought of if I had not seen your video. Beside IF you don't have an expensive R134A recovery tank, and most people won't, you loose all that refrigerant if the pump is bad. So your technique is good for the environment bro! LOL Thanks for sharing. Best Wishes & Blessings. Keith Noneya
30 seconds is to long for no oil , I use 5 seconds it is all you need to see compressor turn on and see Gage move, it will not read the same as if it had 134a in it.but can see if it is pumping.
Thanks for another good video scanner Danner this is the one I was looking for I never did make it to the other website thanks again be blessed you're the best
Thanks from Australia for the information, I have a KJ Jeep with a slow leak that is impossible to locate. I tried leak testing with no success and as the system is empty I’ll try the compressed air method to locate it this time.
Proof that when you know what you are doing, it is easy. Great job! Really like your book. May have to subscribe to the premium channel again. Thumbs up video.
Thanks for posting. I just finished an AC install in my 1965 Dart and wouldn't hold a vacuum, so was looking for the best way to test and wondered if nitrogen was essential. Glad I found a video where compressed air is used since all I have and didn't want to waste a can of refrigerant looking for the leak. Used a new Sanden compressor, made my own hoses (Master-Cool crimper), but vintage condenser and knee-knocker climate box. The later use flare fittings, which are metal-metal. Found a big leak at the condenser outlet flare fitting. Connecting each flare side to a plug held pressure. Worst-case, I have a copper "soft seat" I can add at the flare (also made in aluminum). Not worried about a hypothetical explosion since no refrigerant in system yet, and even wonder why commenters worry about R-134A in yours since long-gone (no pressure as-found). I use Duracool (propane-butane) and PAO68 oil which doesn't absorb moisture. I have a filter-water trap after my air compressor, plus the system will sit for days at high vacuum (once fixed) to boil off any moisture that gets in.
Excellent video no nonsense , he is perfectly right if the system has nothing in it pressuring with air is fine .. hell you could even piss in it and pressurise it to check for leaks , once leak located then yes you could use nitrogen for second test or add some gas to it to see what’s going on .... sometimes people just go over the top on this safety and that safety , I’m telling you as ex mechanic all you guys know fuck all happens without that big hammer and that pry bar sorts the stubborn ball joint and mad jobs , u can’t use a toffee hammer like the book says ..video was bang on for me makes sense 👍👍👍🇬🇧🇬🇧👌👌 thanks brother ✊
Dude you are a good feller. And a great mechanic. I get a good vibe from you. Ignore the armchair mechanics. Out of respect for you I'm not going to curse here on your youtube comments section. But I have a better choice of names for these folks. Keep posting brother!!!
Armchair mechanics are not the problem, bitter people are. There is nothing wrong with this method if the system is gone, no pressure. This video helps the average guy with an older vehicle who doesn't want to spend 1K+ at a shop to figure out what's wrong, even if that shop is worthy. Yes, Dan is a good guy, most of us aren't working on 50K SUV's and Trucks. If you have one please just take it to the shop.
I had a very odd issue on my 83 Mark VI. A leak that only leaked when the ac was cooling I vacuumed system it held vacuum for 24 hours, charged system and cooled great for 30 minutes then went warm, low Freon. Pulled out what was left in system with my ac machine and stored in recovery tank. Then rigged up a fitting for air line. Pressured up to 120 psi, held great 24 hours, retightened all lines to be sure. Recharge it with dye. Cooled good for 30 minutes. Found the dye dripping out of the ac box under dash . So I replaced the evaporator core. It cured the problem
The problem with using moisture laden air is the fact that PAG oil which is used in most automotive refrigeration systems is extremely hydroscopic. If the oil is replaced with a modern synthetic alternative which is not hydroscopic, there is no issue with using compressed air to pressure test. It’s never a great idea to introduce any moisture into a refrigeration system in the first place.
It's good. You can fix your AC yourself. It doesn't cost an arm and a leg. A few new seals, or a bit of hose or welding down the machine shop for next to nothing, $50 of gas and you are back in action. Beats handing control of your machine over to people who want to charge up as much labour and parts as they can for mending something so simple.
Orfice tube and expansion valve if high pressure high low pressure low...restriction as well. Good catching yourself..i was about to mention that receiver dryer..lol Great job on the air test. But like you said just bc you find one leak doesn't mean it isn't leaking elsewhere recheck with sniffer or dye. Dye check the evap drain tube.
I always found it odd how they said the refrigerant goes up and attacks the ozone but our sniffers have to be placed under leaks as the refrigerant is heavier than air..lol
I used compressed air to pressure test lines on my home AC install with a Goodman condenser. The filter is inside the condenser so I see little benefit in pressure testing lines with Nitrogen since you are going to vacuum anyway.
You're videos are addicting, I am going through your videos I saw the one about UA-cam shutting down your site and you are transferring all your videos. It is hard to follow the time line. Any way, you put alot off time and effort and it shows. I would not worry too much. People will follow if they want to learn. I know I will.
Everyone has an opinion, good or bad. It's so easy to be mean, but ScannerDanner, I will give 5 or 5 stars for showing a method for the average guy with a garage, some tools and a compressor. While nitrogen with a little refrigerant used with an electronic leak detector is dealership best practices, but we all know that most don't have nitrogen equipment sitting around. Best practices always starts with a good visual. Seeing oil on an A/C component is a good note to make, then confirm it. Using shop air with 110 - 130 PSI, high concentration of soap works, but gaining access or getting an eye-ball on any given spot is hard as todays vehicles shoe-spoon engine and everything into the tiny cavity called the engine compartment. How many time can you drop a 13mm impact swivel and it never hits the ground. Hate it you have a 20 minute job, drop a socket and spend 40 minutes looking for it. Some would say, who cares, but that SnapOn socket is $32. People need to understand that pressure switches, pop-off valves on compressors, electronics control everything as you pointed out. No R134a, no lube flow, compressor goes boom. The PCM may shut of the A/C upon WOT to add power, but also to protect the compressor from high rotational forces that can cause internal failures. A few seconds on to "See" activity from A/C control is quick and you did that well. Most DIYers' have to understand that this is instructive information. If it is beyond their abilities, take it to a professional with equipment is best. I want everyone to know, do NOT buy the leak seal goo with dye and a squirt of refrigerant, usually with POE Ester oil in the cans..... NOT ok for any system. I would flush to get that out. For the DIYers' the "Receiver/Dyer" is used with a TXV as it will adjust to cool until almost empty. O-Tube systems are fixed, so too much juice, it floods the Evap, liquid has to got into an Accumulator to boil off and turn into a gas. Liquid cannot be compressed, so over-filling is too easy when R143a systems hold 1.4 lbs.(+/-) unless it has rear A/C. Small car, less, read the label underwood as we do. This is two cans of 12 oz into an empty system. More is NOT better! Also the longer the system has been empty, I would change the dryer, but under a vacuum, use a hot air gun on the dyer to help it boil off moisture. But how good is it afterwards. How many times has it gone empty before with out changing the dyer. Over All, Good Job! Thumbs up. ASE Master Tech since 1978 / Retired.
Not problem to push a bit of shop air to find a leak provided the system is empty (the case here) and system pulled to vacuum for 30 mins after parts replaced to remove any residual moisture from the system having NO pressure for a long time and the shop air. All good.
Nice video. As for testing for additional leaks after replacing the condenser and receiver drier, it seems once you pull the system into a vacuum you will verify if you need to search for any additional leaks by the fact whether the system is capable of holding a vacuum. The discussion about the flammability of R134a with the introduction of compressed air is news to me since it is not a hydorcarbon based refrigerant. When servicing a/c system the procedure I follow prior to recovery of refrigerant is first to identify if there is any sealant; next, and hopefully no sealant present (sealant will destroy a refrigerant identifier), use a refrigerant identifier to verify you don't have contaminated refrigerant (no propane/butane (if present, now you have a flammability issue)) introduced into your pure refrigerant. If no contamination present, proceed to normal recovery. If contaminated then special procedures must be followed. Note: fluorescent die does not damage a refrigerant identifier. It seems there is some "blending" going on with testing for leaks (an a/c system versus an evap system). In a perfect world one would use nitrogen with their smoke machine, rather than compressed air, when testing an evap system because introducing oxygen into the fuel system creates a situation that only requires an ignition source to ruin your whole day. In reality, the shops that I have worked at have such a small amount of nitrogen (used in conjunction with the low pressure fuel evaporative test (LPFET) portion of an emission test on pre-1996 vehicles), or none, compressed air is the only option available when using a smoke machine.
Hey ScannerDanner, its anthony from the side of the road! :P me and my dad would like to say thanks again for helping us get home. Impressive channel btw!!
Just watched this video, that is a great idea. Although i would have taken a look first with the uv light and yellow glasses, since you said, and i suspected, that the water/soap mix would wash away the evidence of the leak. That would have helped to narrow down where to look for the leaks before spraying the water/soap mix. Also, it would help to have the car on a hoist, as sometimes access is better and/or easier from the bottom.
You must be implying that there is a dye in the system to use the UV light. And that's the way I would have suggested as the dye should have been real easy to spot. I would waste a what is now about $8 can of refrigerant/dye for checking as you would probably be able to get 20 psi for checking pressure which should be plenty. I'm just not a big fan of purposely injecting air in a AC system for all the reasons already given.
Most cars since the mid to late 90's have the dye in the refrigerant put in when the car is built in the factory. But, using air is a cheap and quick way to try to find leaks, as it does save on putting more refrigerant into the system just to find a leak. However, so leaks are so small, it's better to put dye in and top off the refrigerant and have the customer return in a few days.
The compressed Air method works great, but sometimes the leak is so small that the only time you be able to see it is under high pressures (200+). I ran into this issue the other day. Small leak on the condenser would only bubble when the AC is on.
Powerful car A/C compressors will easily pump way over 200PSI (300PSI on the high side on a 4th gen Z28 Camaro on a real hot summer day for instance ... think AZ desert "loco" day), and you need to be able to check such pressures. Most of shop air that I know go 120 - 150PSI max, I haven't ever seen one going 300PSI. I don't know ... nitrogen pressure test seams to be the acurate way to do the job, AND you don't further pollute the A/C system with air moisture. You know of any shop air that goes 300PSI (brand, model) ??? By the way, you can weld together a 1/4" SAE adapter for A/C pressure testing. Anyway, nice video! I discovered the channel lately, I really like it. 2 thumbs up!
Nitrogen is better to use than air from a shop air compressor. And that was a question on the ASE Air Cond certification test back in the 1980's - about the time of the change from R-12 to HFC-134 was finished.
I NEVER MIXED COMPRESSED AIR WITH THE REFRIGERANT! IT WAS EMPTY FROM A LARGE CONDENSER LEAK!
Some of you want to argue, that what I showed was unsafe. Please tell me how an empty system, filled with compressed air, is a safety concern. I'm not asking about the supposed contamination. I am asking about the safety side of this procedure. I certainly do not endorse unsafe practices.
Here is something I found on a Google search from some engineer forum...
HFC-134a is not flammable in air at temperatures up to
100 deg. C (212 deg. F) at atmospheric pressure. However, mixtures of HFC-134a with high concentrations of air at elevated pressure and/or temperature can become combustible in the presence of an ignition source. HFC-134a can also become combustible in an oxygen enriched environment
(oxygen concentrations greater than that in air). Whether a mixture containing HFC-134a and air, or HFC-134a in an oxygen enriched atmosphere become combustible depends on
the inter-relationship of 1) the temperature 2) the
pressure, and 3) the proportion of oxygen in the mixture. In general, HFC-134a should not be allowed to exist with air above atmospheric pressure or at high temperatures; or in an oxygen enriched environment. For example HFC-134a should NOT be mixed with air under pressure for leak testing or other purposes.
ScannerDanner some one touch a raw nerve. I also have seen in a Mazda service manual a caution not to use compressed air due to possible ignition of gasses. In Australia we use inert nitrogen to test the system's compressor function, but do as you do bro. The system should also be flushed with compressed air and solvent. Also I found many videos demonstrating how the charging system of a vehicle works, your last explanation was not clear in your last video due to language difference such as "control wire". Nevertheless the control wire switches the solenoid and the main power wire from the battery goes to the B+ post. Thanks for clearing that up bro.
If you caused an unsafe condition by using compressed air, then I'm going to buy a lottery ticket tonight and WIN, and then I'll take you, and ALL the subscribers of this channel on a cruise with me next week. :)
In other words, we've got a better chance of being struck by lighting ... TWICE ... and winning the MA state lottery ... in the same hour.
The Google search quote is straight out of the Material Data Safety Sheet (MSDS) for Dupont Isceon M099, i.e. HFC-134a.
The take away from that would be to not expose the pressurized, hot air/HFC-134a mixture to a flame or, secondly, use a compressed bottle of 100% oxygen to pressurize a refrigerant system with entrained HFC-134a.
So Paul is perfectly fine to utilize shop air.
Great video.
You summed that up better than I could have. Thank you!
Nope, R134A is not combustible in the atmosphere , so putting air in there works the same way, the negative point by doing this is that you are introducing water vapor in the a/c system but he explained that anyway there was a leak therefore air and humidity were in already.
I had a similar vacuum leak issue on a 2003 Envoy that was dead empty, tried the compressed air at about 70 psi and found the leak in 5 seconds, litteraly hissing out the condenser, no soapy water needed. This weekend will replace the condenser . Great tip and videos as always. Thank You!
Paul, I trained on Automotive AC at the GM training center in Tarrytown NY many years ago. Over the years as a Chevrolet Tech I worked on many different systems and always took the advice of the instructors. They had developed many different techniques that weren't in the book and still aren't. Please continue with your advice no matter what the criticisms are...
What about you share those not in the book? This is a good test but I feel like it is very hard to spot small leaks. In my case I was losing about 10 psi @100 test pressure every 5 minutes. This is a very small leak, cannot hear it and would not be detected easily. My next step is to inject dye and see where it is.
@@scientist100 dye injection should've been your first step. I find leaks in 10 minutes or less. Don't have time to spend 2-3 hours chasing a leak at high volume shops
@@harryazzole7814 only if you can see it. Anything after the firewall requires time that the dye test won't show. I can hear a large leak right away with ease, dye would take longer time to inject and wait for it to show.
What do you mean by dye guys ?
mr Florida guy may I ask u a question.. gmc truck 2015 yukon expansion valve is leaking replaced the seals on expansion and the hoses twice and cleaned surfaces.. still leaking any advice will help..it's driving me insane
Most of your tutorials are 100% money makers. I have used your tutorials for research, diagnostics and repairs. All without issues. Got nothing but great appreciation. Thanks man!
thank you so much!
Both of your A/C troubleshooting videos using compressed air, with explanations of the various systems, is outstanding Paul!! You have made this complicated system a workable one for us DIYers, and plenty of thanks to your fine son in helping his dad too!!!
Thank you jake ounce! And I appreciate your comment about my son too. He has been a HUGE help to me.
Man first off just want to say thank you for your content and the information you share. I was able to find the leak on my wife’s 2011 Chevy traverse and replace the parts that needed to be replaced. The local shop wanted an arm and a leg for the work I was able to get done at the fraction of the cost by watching your videos and investing in a set of gauges and a vacuum pump. Thanks to y’all my wife’s SUV is ready for another hot summer in the high desert of CA.
I will say your videos on ac troubleshooting and repair are the best anywhere. I’ve been quoted $3500 to start on ac fix. With your help I’m under $1000 with rear evaporator core, compressor, r-134, and vacuum pump and manifold gauge. Thank you for videos!
Thanks for this it saved me wasting expensive refrigerant. I put the money I saved towards a small compressor instead. The stethoscope tip from another reviewer will help in hard to reach parts of the system. I cant do any physically demanding work on my car due to poor health. Your video has empowered me to tackle this job myself. I will gain that sense of achievement from doing it myself. Thanks.
Love this video! Pulled my system apart yesterday, removed and flushed out all the lines and added a new compressor, condenser, expansion valves, etc. Buttoned it up today and pulled a vacuum, but it wouldn't hold very long. I was weighing my options on how to find the leak (including pulling everything apart again), found this video, pressurized system to 50 lbs, and voila! One of the dryer lines had a slice in the new o-ring and the connection was bubbling. Swapped out that o-ring, and now it holds a vacuum. Thanks so much for posting.
awesome Bill! That's what I'm talking about. Thank you
.......Nice to hear someone speaking clear english while doing a video. Some of these tech videos move so slow relaying pertinent information , that I can't even get through the first thirty seconds of the video. Thanks for an informative production.
thanks so much! I like to hear comments like this. I am a teacher after all and this is good feedback
It is me again Paul. This is the second video I have watched and I like your common-sense method of diagnosing leaks. I am 71 but interested now in learning how to diagnose and repair vehicle AC systems. Gotta keep my mind plugged in. Thank you for taking the time to produce these free videos. May God richly Bless all that you do and your Family as well.
Agree with you good common sense information that a guy can do at home with the stuff he has I also know people that have used compressed air to find leaks they never caught on fire or exploded and when finished they had cold air and no customer complaints Thanks Scanner Danner
Have been doing A/C for 42 years .I have been using compressed air with moisture filters , air used to paint cars, Must use moisture free ai,r I have seen air hose blow out a ounce or 2 of water that would be impossible to vacuum out of the system .1 system is empty or. Recover system .2 add 150 psi paint air.3 I now use a Robinair ultra sonic leak finder , it hears leaks finds leaks to 1/2 ounce per year. then use soap and water to show customer the leak used soap and water before I had the Robinair ultra sonic. I do over 1000 cars a year.
Thanks. That was my concern.
Does the dryer/ accumulator have to be changed when the system is open to air for a period of time?
@@rcaddict3815receiver dryer as in this case yes. He said it in the video too
It's funny how some people are such experts on Y-Tube. Experience means nothing. Better not undo a fuel line, two drops of fuel might explode into a raging inferno. I have been repairing A/C systems for over 40 years and I have never had a problem with using Nitrogen, compressed air, electronic or refrigerant (R-12 days) while testing for leaks.
In real life repair you do what you have to do within the limits of your knowledge and experience. As far as moisture goes, on the assembly line they pump em down for 10 seconds and then fill them. I guess that's why they install a drier. A tip for soap, Dawn liquid dish washing soap seems to make the most bubbles.
Well done, Paul in my opinion.
You are correct if it working on a car that's been around a long time I would do two things change the expansion tube or clean it change the filter drier accumulator because of a bag of dust in the dryer degrades and can break I've seen that and you got one hell of a son of a b**** in mess
This is probaly one of the more helpful videos I've come across in my searching for the last week about the proper way to do this.
Good to see that you actually tracked down the problem... love the use of compressed air instead of nitrogen. quick and dirty.
I was ready to take this system I just built to the shop and pay$$$! New compressor, condenser, accumulator, and orings all around. Yet, I couldn't maintain any vacuum. Your simple and straight forward approach - I found my leak. You are an obvious genius~! Thanks...
Awesome man, that's what I'm talking about
My main job is mobile car AirCon. Over here people are under the impression that car AC systems just need ‘ topping up ‘ every couple of years. As if the refrigerant is a consumable substance...
Anyway, this video is brilliant, and is exactly what I was looking for a couple years ago when starting out. Really thorough and full of facts!
The only thing I do differently is that I use oxygen free nitrogen to pressure test. But can’t see a huge problem with using compressed air as long as the system is thoroughly vac’d afterward.
Bang on mate.
What about the AC dryer people keep talking about going bad automatically with compressed air?
Great video. Your comments are right on. Most show a simple video they copied for elsewhere and don't really understand it. You actually thought this whole thing through. Smartest video so far. Thank you!!
Scotty also pumps air into an empty system. He has a very sensative listening device with a long wand. He can HEAR the slightest hisss of leaking air thru his headphones. Anyone who took the time to watch his video would know that. Nobody knows everything. There are new tricks to learn every day. His new method even finds leaks behind the dash.
Years ago I worked for IBM and I did an upgrade to a 3715 printer. The upgrade allowed the printer to print faster and an easier to install ribbon. To make the printer faster all you had to do was move a jumper. I took my time doing the upgrade because I felt bad for the customer because if they knew they could have done the upgrade on their own and not paid all that money for me to do it they might have been upset. My point being some of these guys don't like you coming along with a test light or some compressed air and using sound logic to figure out a problem. They want to come in with their bells and whistles and magic and behind a curtain like the Wizard of Oz fix the problem. Knowledge is power and you are helping people just like you help your neighbor when he needs it. You can relate to this. I fixed a Chevy Impala once that was having trouble getting it started. I told him it was his carb and he needed it rebuilt. He asked me if I could get it running so he could get home and his brother in law told me not to do it for free so I told him I'd get it running for 25 bucks he agreed. I went out and had him crank the engine while I tapped the carb to unstick the float and it started. He said 25 bucks was a lot of money for just tapping his carb so I told him okay 5 bucks to tap the carb and 20 bucks to know where to tap it. Great vid Brother.
Your logic is sound and sometimes you have to read the directions or in this case listen as you qualify the condition of the AC system. GBWY
nice! Loved that. And that is exactly it too. We get paid for knowing where to "tap" :-)
Thanks man
Compressed air to test ac system leaks is definitely going into my arsenal of diagnostic methods...Any nay-Sayers are apparently oblivious to the fact that once repaired, the system will undergo vacuum to remove air moisture before recharging...
exactly, not to mention the system if full of atmospheric air already when there is an empty system from a leak.
BTW, I would recommend using something called Seek-a-Leak which is designed to find leaks on tires, similar to soapy water but better results...Works great for leak testing tires as well as any pressurized tank, hoses, fittings, etc...Also, would like to take this opportunity to thank you for your great book, one of my best investments and diagnostic tools ever!...
But wait... I get if it's a leak and you're trying to find it. The filter drier is already gone as once the refrigerant leaks out, the air can and does come in. It won't hurt to use compressed air at all in this case.
But what about leak/pressure testing on a newly repaired system? Wouldn't you want to avoid exposing the newly replaced filter drier to moisture and use nitrogen instead at that point?
ONLY if you want to change your dryer and expansion valve. ANY moisture added to the vacuum system instantly ruins an AC Dryer. NITROGEN - NOT SHOP AIR is a MUST or vacuum and use freon. He literally just ruined that cars AC system- sure, it will work in the short term, but never work correctly again until the dryer is replaced.
POE oil absorbs moisture that will not be removed just by pulling a vacuum, but I suppose that's not a problem if there was a big leak some time ago and all the oil has to be changed anyways...
For leak detection, use a borescope to see inside enclosed areas.
Thank you for this video. Been fighting a leak on a completely new replaced system on my 86 mustang. Wouldn't hold a vaccum so I could add refrigerant. This let me find the leak in the brand new pressure switch. Replace switch, now it holds vacuum.
Thanks for the video. I added 2 cans of refrigerant and 2 days later, no AC. Now I know how to find the leak.
An old timer told me that kid's bubble liquid works very well for finding leaks. Ever since then I've mixed 50% bubble leak detector with kid's bubble liquid. Works extremely well for small leaks.
It contains glycerin, which helps keep the bubbles from breaking.
To make adding or maintaining pressure easier, get yourself a high side quick connect and put an air fitting on it. That way you can run air to it all the time and not have to go back and add any if you bleed off.
Hello, I am trying to find a leak in my 1999 F230 super duty... can you tell me what fittings I need to buy to fill the AC system with air using guages..(that I will purchase too)
Go to an auto parts store and get a high side coupler and screw in an air fitting of your choice. The threads arent a perfect match but put some teflon tape on it and it will seal up just fine.
Wonder if anyone actually makes an adapter for this purpose, or is it considered too "taboo" to sell, like an extension cord with two male ends-
Strictly a DIY item I guess.
Save your trigger fingers (unless you're into body building) and try using a pump lawn sprayer (mine from HF). Works great for flat repairs too! The long tube gets into tight spaces as well. I fill it maybe once a month. After 45 years the hands get a little painful squeezing triggers.
that's a good idea! I have two of those two. Thanks for the tip!
I learned so much from you. Thank you for these diagnosis videos.. fixed all my AC and fuel system issues by watching hours of your content.
Awesome! Thank you
I had a compressor front shaft fail in my 86 mustang. That was fun to find! It held a vacuum all day long, but could not hold the refrigerant pressure.
I have seen this too. Thanks!
I came looking on how to introduce compress air to my impala ac and this video did not disappoint. I didn't even type Impala and it was the first thing that popped up. Awesome work guys
I would also also like to add. The cheapo trigger pull freon gauage valves that you get on like an AC pro has the same female threads as a air compressor male connector
Great video never thought of using compressor air.
Just did this. Found leak at connection to compressor in five seconds. Changed orange and pulling a vacuum. Great way to look for leaks.
Used this method on my 2000 ford Explorer and found the body of the compressor leaking ever so slightly. Thanks Paul.
I just used this method and had a heck of a time finding the leak, turns out BOTH service ports were leaking. I have two dryer filters on my air line so I wasn't worried about moisture. I Vacuumed the system down and it held! This was on a 2000 Tahoe. Thanks for the video!
Did you just listen for the leaks there instead? Or just release the pressure from the gauges and check for pressure coming back up without opening the valves?
@@dubmob151 Soapy water in a spray bottle.
I always replace the TXV if I had a compressor failure... you nailed it
Hello my friend Paul
I always wanted to see how someone can check ac leaks with compressed air. Absolutely a awesome video Paul. Your son is quite some camera man. God Bless the whole Danner family
For sure! And I've been using this method for 25 plus years. I'm spite of the supposed issues with it that others have.
Thumbs up,right off the bat; i do the same thing; for over 30 years.
The only thing --remaining-- is under the dash,inside the car; and for that you need at least a small charge of "freon" and the electronic "sniffer".
good video..this is the time that an ultrasonic leak detector is invaluable..it hears compressed gases coming through small holes that are out of the bandwidth of your ears....it can hear compressor shaft seal leaks and evap cores leaking. they're not perfect but gives one another tool in your diagnostic kit ...mines has pulled my butt out of many problems..look in to it..you won't be sorry...
Preparing for my A7. Going over your AC videos. Need to learn more on the diagnoses section
Have used soap and water on a lot of different systems on heavy truck repair,,, will def try this one!
Update! Just did this on a international 4300 truck,,, found the problem in about 2 minutes,,, we get quite a few small leaks in the big truck World at our shop ,, thanks again for the info!
Perfect video. Shop air is a great idea. No need to waste refrigerant and dye
Thanks for quick reply. Will check the Orifice tube and dryer parts. Have not used air con as you suggested. Bob
I was gonna bite the bullet and buy one of those ac leak dye. Now I'm gonna go ahead and pressurise my ac system looking for leaks. Cheers man!
Good information. I've also had pretty good luck using an electronic stethoscope to track down major leaks after pressurizing.
I have deep feelings for and about this one. It showed how to tell the compressor still works !!! when I'm and my beloved is coming from like situation of emptied system dry from leak ...right? Been left without working it sporadically to keep it I'm shape.
But mostly it determines compressor does function and I haven't hurt it.
Just a thought. You might consider dye along with the compressed air and increase the pressure to 250 once equalized. That would find ALL the leaks without starting the system for more than five seconds.
Thanks for the video despite the youtube trolls the rest of us appreciate what you have to share.
That comment you made about compressed air is what I've always thought. In fact I made a little piece to connect to my compressor and my manifold gauges. I fill my system up to about 100 PSI every time I do an AC repair just to check it and I've always thought that the vacuum process would eliminate any moisture that the compressed air may cause...... AND I've never had a problem in the decades I've been repairing cars.......
At 500 microns, all moisture is out.
About to do this procedure later today or tomorrow... at least before it gets too hot out. Thanks SD always the best troubleshooting tips on YT
"one rubber-tipped air nozzle coming up"
for some reason i found that funny
I have a small flask of ultra pure nitrogen that I like to use for testing. A bonus is that it's a very quiet process and can often hear leaks. I use a UV torch to search for leaks in a dark as possible workshop. The leak will fluoresce under UV lighting.
These past 2 videos you've posted on ac diag are the absolute best on UA-cam. Please keep them coming brother:)
I can't believe I never thought of using compressed air and soapy water to find a A/C leak. Thanks for the video. I do remember the abominable snowman cartoon. When I got older, I realized they were doing a takeoff of Steinbeck's "Of Mice & Men" - George & Lenny.
Fantastic video! Thanks for taking the time and effort to make a quality production. Is helping me much in my A/C challenge with my 1996 Suburban!
Awesome video! I was trying to figure out how to pressurize my system since the fill port on my gauges won't fit my air chuck, but the rubber tipped spray nozzle did the trick! put it up to 120 psi and immediately heard the leak. It is the condenser, looks like a stone hit it. I need to put a screen in front of this thing!
Edit: Condenser was the leak, it was large enough it was hissing like a punctured tire!
I like this method, I have found a lot of hard to find leaks like this. I don't worry about moisture that is what vacuum is for. I do it a little different but end result is the same. Great video as always.
Good Job. I would replace the bad condenser and the dryer ,run a vacuum check and if it holds minus 30 psi for an hour.It is good to go for a recharge.
I found a leak for the first time using shop air the other day. We run some type of filter on our shop air to keep oils and waters out of it so we can paint with it.
The system had zero pressure and had not been used all winter. Turns out a sticky shrader valve was leaking on the low side.
I vacummed it down for an hour and left it vacuumed down one week. Since outside temps sort of got crazy cool again the following week I needed heat in this dump truck and didn't miss the air. My hope was that the engine heat and vacuum would dry out the dryer.
A week later It was still holding vacuum but I vacuumed it down again for an hour. I never changed the dryer which had been replaced the season before and it was blowing 41 degrees in the vents after weighing in the specified 3.5LBS of freon.
I would have never tried shop air before seeing Scanner do it. I usually use Nitrogen and soapy water but tried the air and saved my Nitrogen for another day.
If it didn't work I would have reclaimed the freon and got a new dryer for it. And if that didn't work I'd go back to 2-60 air condition. LOL!
Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air.
Was the issue with compressed air that it may introduce moisture into the system?
@@dubmob151 Further to my previous comments about the dangers of using compressed air to pressure test air conditioning systems please see below quotation which was copied from a commercial Robinair vehicle a/c charging station instruction manual. QUOTE “WARNING: Do NOT use air or any gas besides N2 or N2H2 to pressurize the system. Mixtures of air and refrigerant can be combustible at elevated pressures. These mixtures are potentially dangerous and can result in fire or explosion causing personal injury and/ or property damage” UNQUOTE
SD is excellent 99.9% of the time, but do not agree that it is good engineering practice to use shop air to pressure test AC systems rather than dry N2. ALL introduced moisture will have to be removed afterward. Other contaminants will almost certainly be introduced. There will be traces of oil mist in the air (from the car ac system) which may form an explosive mixture with the air and will be evacuated by a vacuum pump that can get hot. If I went to a dealer or specialist and witnessed them doing this I would be seriously unimpressed!
Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air.
@@dubmob151 Further to my previous comments about the dangers of using compressed air to pressure test air conditioning systems please see below quotation which was copied from a commercial Robinair vehicle a/c charging station instruction manual. QUOTE “WARNING: Do NOT use air or any gas besides N2 or N2H2 to pressurize the system. Mixtures of air and refrigerant can be combustible at elevated pressures. These mixtures are potentially dangerous and can result in fire or explosion causing personal injury and/ or property damage” UNQUOTE
SD is excellent 99.9% of the time, but do not agree that it is good engineering practice to use shop air to pressure test AC systems rather than dry N2. ALL introduced moisture will have to be removed afterward. Other contaminants will almost certainly be introduced. There will be traces of oil mist in the air (from the car ac system) which may form an explosive mixture with the air and will be evacuated by a vacuum pump that can get hot. If I went to a dealer or specialist and witnessed them doing this I would be seriously unimpressed!
Max respect to SD. Since seeing this video I have seen another of his videos where he changes to use N2 to pressure test and points out the dangers of using shop air...
Just found your channel. Great job. Audio excellent, Video really good. Thanks for upload this onto youtube.
Professional, informative video! Many thanks from a long time shade tree mechanic!
Hey Paul im an Ase cert. mechanic here on Puerto Rico i do the same thing but take it o 250psi because sometimes the leak is so small that you cant find it unless you stress the place that is leaking plus the car lines are rated to 500psi+ taking in consideration the age of the hoses ,take care buddy keep on going nice channel
Thanks man. I appreciate your input too!
Nitrogen set at 250 lbs. spray with bubble blowing fluid , this procedure does a fine job of locating leaks
Thanks fro teaching safe and proper procedure. I have seen people use Nitrogen cylinders fort this diagnosis but that seems a little expensive in the long run.
Yep I'll be doing that on my 01 F350 to find the leak. Yep it will be vacuumed out and the Accumulator/drier will be changed before I put the R134A in. I don't see a problem using Air on a system that has NO refrigerant in it at all. Or starting it with air, for 30 seconds, to check the; expansion valve, pump and pressure differential, it's probably no sweat at all. In fact it's a technique I doubt would have thought of if I had not seen your video. Beside IF you don't have an expensive R134A recovery tank, and most people won't, you loose all that refrigerant if the pump is bad. So your technique is good for the environment bro! LOL Thanks for sharing. Best Wishes & Blessings. Keith Noneya
30 seconds is to long for no oil , I use 5 seconds it is all you need to see compressor turn on and see Gage move, it will not read the same as if it had 134a in it.but can see if it is pumping.
Thanks for another good video scanner Danner this is the one I was looking for I never did make it to the other website thanks again be blessed you're the best
Thanks from Australia for the information, I have a KJ Jeep with a slow leak that is impossible to locate. I tried leak testing with no success and as the system is empty I’ll try the compressed air method to locate it this time.
Proof that when you know what you are doing, it is easy. Great job! Really like your book. May have to subscribe to the premium channel again. Thumbs up video.
Thanks so much! You will not be disappointed if you do
Thanks for posting. I just finished an AC install in my 1965 Dart and wouldn't hold a vacuum, so was looking for the best way to test and wondered if nitrogen was essential. Glad I found a video where compressed air is used since all I have and didn't want to waste a can of refrigerant looking for the leak. Used a new Sanden compressor, made my own hoses (Master-Cool crimper), but vintage condenser and knee-knocker climate box. The later use flare fittings, which are metal-metal. Found a big leak at the condenser outlet flare fitting. Connecting each flare side to a plug held pressure. Worst-case, I have a copper "soft seat" I can add at the flare (also made in aluminum). Not worried about a hypothetical explosion since no refrigerant in system yet, and even wonder why commenters worry about R-134A in yours since long-gone (no pressure as-found). I use Duracool (propane-butane) and PAO68 oil which doesn't absorb moisture. I have a filter-water trap after my air compressor, plus the system will sit for days at high vacuum (once fixed) to boil off any moisture that gets in.
Yeah, you'll be fine using compressed air. Nice job my friend
Excellent video no nonsense , he is perfectly right if the system has nothing in it pressuring with air is fine .. hell you could even piss in it and pressurise it to check for leaks , once leak located then yes you could use nitrogen for second test or add some gas to it to see what’s going on .... sometimes people just go over the top on this safety and that safety , I’m telling you as ex mechanic all you guys know fuck all happens without that big hammer and that pry bar sorts the stubborn ball joint and mad jobs , u can’t use a toffee hammer like the book says ..video was bang on for me makes sense 👍👍👍🇬🇧🇬🇧👌👌 thanks brother ✊
Dude you are a good feller. And a great mechanic. I get a good vibe from you. Ignore the armchair mechanics. Out of respect for you I'm not going to curse here on your youtube comments section. But I have a better choice of names for these folks.
Keep posting brother!!!
Armchair mechanics are not the problem, bitter people are. There is nothing wrong with this method if the system is gone, no pressure. This video helps the average guy with an older vehicle who doesn't want to spend 1K+ at a shop to figure out what's wrong, even if that shop is worthy. Yes, Dan is a good guy, most of us aren't working on 50K SUV's and Trucks. If you have one please just take it to the shop.
@@frankgriner2932 . . . .i won't "take it to the shop" I fix it
I had a very odd issue on my 83 Mark VI. A leak that only leaked when the ac was cooling
I vacuumed system it held vacuum for 24 hours, charged system and cooled great for 30 minutes then went warm, low Freon. Pulled out what was left in system with my ac machine and stored in recovery tank. Then rigged up a fitting for air line. Pressured up to 120 psi, held great 24 hours, retightened all lines to be sure. Recharge it with dye. Cooled good for 30 minutes. Found the dye dripping out of the ac box under dash .
So I replaced the evaporator core. It cured the problem
should have went with 200 psi and you would have most likely saw the drop in pressure
The problem with using moisture laden air is the fact that PAG oil which is used in most automotive refrigeration systems is extremely hydroscopic. If the oil is replaced with a modern synthetic alternative which is not hydroscopic, there is no issue with using compressed air to pressure test. It’s never a great idea to introduce any moisture into a refrigeration system in the first place.
It's good. You can fix your AC yourself. It doesn't cost an arm and a leg. A few new seals, or a bit of hose or welding down the machine shop for next to nothing, $50 of gas and you are back in action. Beats handing control of your machine over to people who want to charge up as much labour and parts as they can for mending something so simple.
Great idea to use car wash, I always used dish soap... great video Sir
Orfice tube and expansion valve if high pressure high low pressure low...restriction as well.
Good catching yourself..i was about to mention that receiver dryer..lol
Great job on the air test.
But like you said just bc you find one leak doesn't mean it isn't leaking elsewhere recheck with sniffer or dye.
Dye check the evap drain tube.
I always found it odd how they said the refrigerant goes up and attacks the ozone but our sniffers have to be placed under leaks as the refrigerant is heavier than air..lol
Thanks, for the information given. You seem to be an all rounder, that's cool. Automobile diagnostics demystified.
I used compressed air to pressure test lines on my home AC install with a Goodman condenser. The filter is inside the condenser so I see little benefit in pressure testing lines with Nitrogen since you are going to vacuum anyway.
You're videos are addicting, I am going through your videos I saw the one about UA-cam shutting down your site and you are transferring all your videos. It is hard to follow the time line. Any way, you put alot off time and effort and it shows. I would not worry too much. People will follow if they want to learn. I know I will.
Everyone has an opinion, good or bad. It's so easy to be mean, but ScannerDanner, I will give 5 or 5 stars for showing a method for the average guy with a garage, some tools and a compressor. While nitrogen with a little refrigerant used with an electronic leak detector is dealership best practices, but we all know that most don't have nitrogen equipment sitting around. Best practices always starts with a good visual. Seeing oil on an A/C component is a good note to make, then confirm it. Using shop air with 110 - 130 PSI, high concentration of soap works, but gaining access or getting an eye-ball on any given spot is hard as todays vehicles shoe-spoon engine and everything into the tiny cavity called the engine compartment. How many time can you drop a 13mm impact swivel and it never hits the ground. Hate it you have a 20 minute job, drop a socket and spend 40 minutes looking for it. Some would say, who cares, but that SnapOn socket is $32. People need to understand that pressure switches, pop-off valves on compressors, electronics control everything as you pointed out. No R134a, no lube flow, compressor goes boom. The PCM may shut of the A/C upon WOT to add power, but also to protect the compressor from high rotational forces that can cause internal failures. A few seconds on to "See" activity from A/C control is quick and you did that well. Most DIYers' have to understand that this is instructive information. If it is beyond their abilities, take it to a professional with equipment is best. I want everyone to know, do NOT buy the leak seal goo with dye and a squirt of refrigerant, usually with POE Ester oil in the cans..... NOT ok for any system. I would flush to get that out. For the DIYers' the "Receiver/Dyer" is used with a TXV as it will adjust to cool until almost empty. O-Tube systems are fixed, so too much juice, it floods the Evap, liquid has to got into an Accumulator to boil off and turn into a gas. Liquid cannot be compressed, so over-filling is too easy when R143a systems hold 1.4 lbs.(+/-) unless it has rear A/C. Small car, less, read the label underwood as we do. This is two cans of 12 oz into an empty system. More is NOT better! Also the longer the system has been empty, I would change the dryer, but under a vacuum, use a hot air gun on the dyer to help it boil off moisture. But how good is it afterwards. How many times has it gone empty before with out changing the dyer. Over All, Good Job! Thumbs up. ASE Master Tech since 1978 / Retired.
Not problem to push a bit of shop air to find a leak provided the system is empty (the case here) and system pulled to vacuum for 30 mins after parts replaced to remove any residual moisture from the system having NO pressure for a long time and the shop air. All good.
Thank you for this video ! Audi Technician very thankful 🤙🏼
Nice video. As for testing for additional leaks after replacing the condenser and receiver drier, it seems once you pull the system into a vacuum you will verify if you need to search for any additional leaks by the fact whether the system is capable of holding a vacuum.
The discussion about the flammability of R134a with the introduction of compressed air is news to me since it is not a hydorcarbon based refrigerant.
When servicing a/c system the procedure I follow prior to recovery of refrigerant is first to identify if there is any sealant; next, and hopefully no sealant present (sealant will destroy a refrigerant identifier), use a refrigerant identifier to verify you don't have contaminated refrigerant (no propane/butane (if present, now you have a flammability issue)) introduced into your pure refrigerant. If no contamination present, proceed to normal recovery. If contaminated then special procedures must be followed.
Note: fluorescent die does not damage a refrigerant identifier.
It seems there is some "blending" going on with testing for leaks (an a/c system versus an evap system). In a perfect world one would use nitrogen with their smoke machine, rather than compressed air, when testing an evap system because introducing oxygen into the fuel system creates a situation that only requires an ignition source to ruin your whole day. In reality, the shops that I have worked at have such a small amount of nitrogen (used in conjunction with the low pressure fuel evaporative test (LPFET) portion of an emission test on pre-1996 vehicles), or none, compressed air is the only option available when using a smoke machine.
Wow thanks so much for sharing your knowledge this saved me a bunch of money.
Blessings and more blessings to you and your family
Hey ScannerDanner, its anthony from the side of the road! :P me and my dad would like to say thanks again for helping us get home. Impressive channel btw!!
Thanks Anthony! Great to meet you and im glad i could help.
Just watched this video, that is a great idea. Although i would have taken a look first with the uv light and yellow glasses, since you said, and i suspected, that the water/soap mix would wash away the evidence of the leak. That would have helped to narrow down where to look for the leaks before spraying the water/soap mix. Also, it would help to have the car on a hoist, as sometimes access is better and/or easier from the bottom.
You must be implying that there is a dye in the system to use the UV light. And that's the way I would have suggested as the dye should have been real easy to spot. I would waste a what is now about $8 can of refrigerant/dye for checking as you would probably be able to get 20 psi for checking pressure which should be plenty. I'm just not a big fan of purposely injecting air in a AC system for all the reasons already given.
Most cars since the mid to late 90's have the dye in the refrigerant put in when the car is built in the factory. But, using air is a cheap and quick way to try to find leaks, as it does save on putting more refrigerant into the system just to find a leak. However, so leaks are so small, it's better to put dye in and top off the refrigerant and have the customer return in a few days.
Always good info and gave me 15 mins 55 sec to drink a good IPA beer.
blue moon here brother. happy 4th!
What’s a good IPA beer..? Impossible!
Thanks Man for a great video.
Excellent video, great job, very, very, very professional.
also you have to replace the AC oil that was lost
The compressed Air method works great, but sometimes the leak is so small that the only time you be able to see it is under high pressures (200+). I ran into this issue the other day. Small leak on the condenser would only bubble when the AC is on.
good tip! If there is refrigerant in the system, run it, when looking for a leak on the high side!
You have helped me the most with ac
Thanks for sharing Your awesome video and Professional skills
Powerful car A/C compressors will easily pump way over 200PSI (300PSI on the high side on a 4th gen Z28 Camaro on a real hot summer day for instance ... think AZ desert "loco" day), and you need to be able to check such pressures. Most of shop air that I know go 120 - 150PSI max, I haven't ever seen one going 300PSI.
I don't know ... nitrogen pressure test seams to be the acurate way to do the job, AND you don't further pollute the A/C system with air moisture.
You know of any shop air that goes 300PSI (brand, model) ???
By the way, you can weld together a 1/4" SAE adapter for A/C pressure testing.
Anyway, nice video! I discovered the channel lately, I really like it. 2 thumbs up!
I've been using nitrogen on my newer AC videos. Thanks!
Nice job on this one. Nice camera work from Caleb too. Thanks guys!
Thank you!
was there too much camera movement? Another guy said there was. Thanks!
Only once for a brief moment or two. This was his best work yet and he's getting better all the time! Well done!
It was possibly an edit I couldn't make because I was talking at the same time. Cool, thank you!
Using that method for more than 10 years already. Im using an old AC compressor to pressurized parts.
As a tech i can tell you. For GM cars, always check your condenser 1st. They are notorious for Condenser leak.
Nitrogen is better to use than air from a shop air compressor. And that was a question on the ASE Air Cond certification test back in the 1980's - about the time of the change from R-12 to HFC-134 was finished.
nice vid man. watch all of your videos. best mechanic on youtube!
Thanks bro
Thanks for sharing, a pro always makes it seems easy