Yes yes finally this is precisely what I was looking for. Well presented scenarios with excellent explanations with all the details on why when where to back it up. Thanks for taking the time to do this.
👍 I APPROVE THIS VIDEO AS BEING 100% TRUE AND ACCURATE !. 👍 You did a lot of work pulling videos and putting it together to make this video you did a very good job if I work to make a video it would be like this. AC PRO the killer of compressors 😂 👍
BRILLIANT mate. Plain English. No, bull shit. .very well explained. It's not complicated. Down to earth explanation. You are an excellent teacher.. I am impressed.
Awesome ! Thank you for that super positive comment and thank you for the views. I have about 15 videos on automotive AC. I hope you watch a few more. Thank You Again.
I have installed a new compressor, drier insert, and expansion valve. The compressor is clutch-less. When the system was charged the low side went to about 65 and the high side only got to about 140. The air never blew cold. It was suggested that I might need a new condenser as well. There was a little over four ounces of oil in the new compressor and only one ounce in the old. So I split the difference and added two ounces back into the new compressor. Thanks for the great video
Hello, the pressures are both off. It's like the compressor is not working to it's full ability. The compressor control solenoid (or what ever your car company calls it) is responsible for controlling the angle of the wobble plate. New compressor come with a new solenoid. It could be the circuit that controls the solenoid. You will need to get a scanner that does Body codes. Check for Trouble codes on the AC. What is static pressure (engine off Ac off) after an hour. The blue psi should be about the temp of the day. Start the engine and turn on the AC. The psi on the blue should drop. If it only drops a little bit, the compressor is not working correctly. I wish I could tell you what is wrong. I would research the internet on your vehicle with that problem. Good luck. And yes, it could be a restricted condenser.
@@theoldmecanicoshow9004 Thanks for the reply. The static pressures have been pretty close to the ambient temperature. You are correct that the low-side does not drop enough when the ac is engaged. If the low-side service port comes before the condenser and is reading too high, and the high-side service port comes after the condenser which is reading much too low then does that support the idea that the condenser is bad/restricted?
@@christophercoburn6376 Yes sir. the condenser passages now a days are SUPER small (that how they reduce the amount of refrigerant used) If the old compressor spilled it's guts, the condenser is restricted.
Great video and info. I've got good pressure readings when static and the low and high pressure readings are good when the compressor is running (100 psi on 100 degree day, and 35-40 on low, with 175-200 on the high side), but the compressor is short cycling. It will run for maybe ten seconds before it cuts off the clutch, then comes back on after about ten seconds again. The temps inside the car at the ducts are good when the compressor is running, but it doesn't run long enough for the interior temps to drop on a hot day. I'm not seeing the pressures go out of the above readings when it cuts off the clutch. The compressor and TXV have been recently replaced. Looking at the condenser, the temp at the inlet is about 150 degrees, but about two inches away it has dropped to about 130 degrees, and just then after another few inches, it is about 115 degrees. I was leaning towards replacing the condenser and dryer to ensure that I don't have an internal plug at either of them. Curious if you think this is a reasonable approach, or am I looking at it wrong. Thanks in advance for your help.
100 psi static is a "BASIC" indicator of the amount of charge. 175-200 psi sounds a little low on the charge. See is you can get the "Exact" specs for your vehicle. It does not sound like the condenser is restricted. Don't get carried away put more Freon. Half a can at the most. Good Luck.
WOW...! You watch my video from the other side of the world. WOW...! Thank you for the view and the comment. Did you see that I have 16 videos on automotive AC. I hope you watch a few more. Thank you.
Hello jakespeed63. About the only time I have seen those kind of readings is when both the handwheels on the manifold gauge set are in the open position / or not fully closed. Both handwheels need to be closed when reading pressures. Was the AC cold?
Thank you for the great video!!! Problem I’m having low pressure side reading 100 high side reading 150. 09 Dodge Ram 1500. Condenser, compressor, expansion valve, and evap were replaced 6 months ago. Everything was working fine. About a month ago was not getting any cool air wile idling only when driving for longer periods. Then stopped working blowing cold all together. Condenser/Radiator electric fan went out I replaced it. Hooked gauges up and got these readings today. Any tips on where to start? THANK YOU
The Oil can be kind of tricky to get right. Did you you flush the AC system? How much oil did you add to the replacement compressor. Replacement parts can be very poor in quality / how long they last. I would empty the system/ pull a vacuum and slightly undercharge the system. If the blue psi is still high...the compressor was probably damaged when the condenser fan gave out. Does the 09 Dodge Ram use a clutch-less compressor? If so...the compressor valve can cause those readings. Good luck.
So how do you get the PT chart for each specific vehicle and region? I'm here in Houston TX, but you state that each PT chart is vehicle specific. Where is the best source to get the charts or what sets of charts do you recommend?
hi World Ford Ranger twin condenser low side 25--35psi About 28psi is freezing point high 150--160psi engine idling and engine at 1500rpm All that on a 110 F day B4 the 2nd condenser was fitted it was terrible at 290 psi high vents temps were 60F R12 =R134a high pressures . Modern car makers use small condensers . Old school R12 was 150--180psi always under all hot climates . Some industrial applications 100-150psi
Wow! Glad I came across this. Very helpful. I do have a situation where my low side is at 35psi and my high side is at 70psi after a fresh recharge. Compressor is running. System is NOT cooling. I'm thinking bad compressor which I could probably replace myself but not sure if there is any other damage to system. Any tips would be greatly appreciated! Thank you again for the great video!
Thank you for that Positive comment. Bad compressor show up on the low side psi. Your low side psi is good. Sounds like you have a restriction somewhere. Watch tis lesson: ua-cam.com/video/mD0K4ZFiRuk/v-deo.html I hope that helps. Thank you again.
@@theoldmecanicoshow9004 my gauges read 45/250 psi amnient temp is 83.inside vents doesnt go below 60 even when I put water on the condenser. I pulled the freon out and pulled a vac the refilled with 25 ounces and same readings. Any advice? Thank you
@@Rekairbrush I hope I can help...each vehicle is different. Some vehicles are colder than others. Here is my suggestions: try to find the factory specs and see what they say (not general specs) make sure the recirculation door works (do you know how to do that?) the oil is important (the correct amount) clean the condenser fins (external cleans) less is better (minimum Freon...not max charge) any problem with the air mix blend door will rob the cold / good luck...what kind of vehicle ?
@@Rekairbrush I hope I can help. Each vehicle is different. Try to get the factory specs (not general specs) Make sure the recirculation door works (do you know how to do that) If the suction line is COLD to the touch and vent is not that good...now you have a problem with the air mix blend door. The oil is important (correct amount) Less is better (not the max charge / minimum charge is better) Good luck...
@@theoldmecanicoshow9004thank you!! I'll look up the specs. What I do know is I replaced the compressor with a used one a couple years ago because of clutch problems and I added the correct pag oil and freon amount. I'll check the recirculating door but have set it open before to no recirculation and still got cold air atleast 50 degrees at vent so I don't think its the issue. I also noticed the low pipe doesn't feel frozen it's cool but not cold and sweating. I was wondering if this could be expansion valve issue? I did pressure wash the condenser to no change. Thank you again for your expertise!
Great stuff Hoss!! Question- I see higher end manifold sets without the sight glass on them like yellow jacket and Mastercool.. Is the sight glass on the manifold needed to pull a vacuum ??? I am hunting a good set and most of them with sight glasses look like El Cheapos.. Thx
The sight glass is a nice "Bell and a Whistle". Everything can be done without the sight glass. I remember my students would get a Kick-Out of seeing the Freon move into the system, that's the only time it's nice to have. Thank you for the question and the view.
Nice video. I have a 2004 chevy impala 3.8 v6 cold air comes out of the passenger side and regular fan air on the driver side and the heater does the exact same thing hot air on the passenger side and regular fan air on the driver side. No one can tell me what it could be. Took it to a couple of mechanics and they dont know. Hope you can give me a good place to start. Been dealing with this for a couple of years. Thank you in advance.
Thank you for that positive comment and the question. Three minutes and ten seconds into this video: ua-cam.com/video/-cuKGAe10QU/v-deo.html explains the "Dual System. The driver electric actuator needs to be replaced. Some actuators are kind of EZ to replace and some are very difficult. Do a search on you tube for your vehicle on replacing the drivers "Temperature" actuator. Good luck.
your video is great. i have a question, so i have a 2006 acura tsx i changed the cabin filter and condenser 3 months ago. recently it started to short cycle when driving above 3000 rpm non stop. at idle it does not short cycle from a cold start only after i driven it, or after the pressure stabilizes. i had the system evac and recharged, it blows cold at idle, shop noticed the low side drop to 12psi when i rev it to 3k rpm and suggested to change compressor so i did. i got new compressor installed and 16oz of new freon, no more short cycling at idle or driving BUT does not seem to get as cold as the old compressor. im out of ideas
The lower the blue pressure goes, the better the compressor is, and when the system is slightly undercharged, the colder it is. Vent temperature is determined by the blue pressure. After market compressors, and rebuilt are sometimes not as good as the factory compressor. It is very EZ to overcharge the system now a days. More Freon is not better, in fact I always put the minimum charge in the system. Have the pressures checked. If the low side is not in specs, have a little bit of Freon removed. Thank you for the comment. Good Luck.
@@theoldmecanicoshow9004 thank you for taking the time to replay to my question. i understand and it makes sense except for the part that when the low side gets lower the better the compressor is? do you know what is the temperature differential one should except on a good working AC system. for example if its 107F outside there should be a 40 degree difference out the vents? so it would be 67F at idle with car being in the sun all day window up non air circulating. I know house AC good system has a 15-20 degree delta from outside temperature. Do you know if one can charge the car ac system using subcool and superheat. for example if subcool temperature is high than your superheat than your overcharged the system. if your subcool is lower than your superheat than your system is undercharged.? today i user a digital temperature because i didn't have a metal one. 30min driving in 106F weather with windows up and air on recirculate my temperature out the center vent was 46F.
@@joeydelmarsjr.646 46F is excellent when outside temp is over 100 degrees. It take time (over 5 minutes) to start to make the inside of the vehicle comfortable.
Had bad compressor, clutch not coming on. Replaced it and charged back to specs on the r134a. I have started the truck and then after 15-20 seconds the high hose from condenser to ac compressor cracked . What will that cause? to crack the high side hose? Plugged condenser? maybe ... restriction in the high side ?, or... thanks for the video.
Yes, more than likely plugged condenser. Starting in about the year 2000, the new style condenser have "Tiny" passages. The tiny passages allow for the manufactures to reduce the charge amount in half. If your bad compressor puked some of it's guts, the condenser is plugged. Thank you for the view and the question. Break a leg / Good Luck my you tube friend.
@@theoldmecanicoshow9004 Thanks for reply. I have order all new parts and waiting to arrive. Will see what happens after they are replaced. Have a nice one.
Wondering if you can provide some insight...so after some repairs my truck's a/c cooled pretty well on a hot day, although it took a while to get it down to that temperature each time I drove it. A month and a half later it suddenly started not being able to get below 60 degrees on a hot day. Here are the repairs I've had done in the past couple months: -Leaky A/C Evaporator was changed out, and since that was the only leaking part in the system, there's no chance of a leak or air getting into the system...refrigerant levels also haven't gone down so that confirms the system is sealed -My high side line and orifice tube got changed out and so it'd doubtful at best that anything is wrong there -The fan clutch got replaced, the condenser has no holes in it and the airflow is proven to be more than adequate, so that can't be the issue -The refrigerant levels were appropriate for the system, but the pressures were both a bit high. I also noticed the condenser was pretty warm when I drove it back to the shop after test driving it today with the new fan clutch. I can only fear that the compressor is starting to fail or there's a block in the system somewhere. The only thing is, where would a block come from suddenly other than the compressor beginning to come apart internally? What do you think is causing this? I've been plagued with 13 years of one A/C problem after another with this truck and I just want to get it resolved. I'm gonna follow up with the shop next week but they weren't sure what was going on today with it.
Thank you for the question and the view. Works... Does not work....AND KIND OF WORKS. The compressor is a big player that Kind-of-works. When the compressor "Weak" the low side is too high and the high side is normal to low. You say both high and low pressures are too high. You said the condenser feels warm to hot. The passages on late model condensers are very very small. They get restricted and that effects the cooling of the AC. Today, when they do a compressor job, it is recommended to replace the condenser. AC is a luxury. And luxuries cost $$$$. I hope I was of some help. Thank you again.
@@theoldmecanicoshow9004 This was helpful, yes, so thank you! Just to be clear, though, how do condenser passages get blocked being that it's a closed system and stuff can't come into it from the outside? Also, the condenser is original to the truck (2000), so does that count as "late model"?
@@GamingDrummer89 Pieces of the compressor and desiccant from the drier accumulator will restrict the needle size passages. I will attach a link on the next answer.
@@theoldmecanicoshow9004 Forgot to mention...my accumulator was changed out along with the orifice tube, so how could the desiccant bag have failed already? Or can a compressor have small pieces coming off inside even if it's not running weakly (like you said it wasn't since the pressures are high)? Does that mean the compressor is on its way out?
I have a Honda with pressure readings of 125 psi on the high side and the gauge is pegged as high as it will go on the low side. Ambient temperature 80 F. I’ve never seen anyone showing these gauge pressures in their demonstrations. Compressor probably shot or bad condenser. What do you think?
Thank you for the question and the view. Either the compressor is not engaged / the handwheels on the gauges are open / or the compressor is completely worn out...like Old Mecanico
On my combine. I replaced the TXV. I'm getting 250 on high but 10 on low. Around 100 degrees F. What could be the issue. I get about 65 degree air in the cab.
Half the time the Aftermarket replacement parts don't work as well as the factory part. Also make use you added the correct amount of Freon. I always charge the Minimum amount/ not the maximum amount. (less is better)
There are two types of gauge reading charts. Generic and specific. Both of these were used on my video. Both came from the Mitchell Pro Demand reference software we use at the college where I taught. Each motor company is different, very different. Some motor companies give you every spec you want and need, and some other motor companies give you NOTHING ! The Asian companies are usually the best / American co. are OK / Euro's are the worst. All of my experience comes from the Pro Demand. I can only guess that the Euro's want you to purchase their manuals and I guess the specs are there. The best specs are the ones that include the changes with ambient temp and humility. The Pro Demand is not cheap. (several $1000) And you are not guaranteed to have all the specs you need for the different vehicles. To answer your question...there is not one source that will provide you all the specs you need. Each motor co. wants you to purchase their manuals. Thank you for the view and the question. Did you notice that I have 15 videos on automotive AC lessons?
Its a shame that this channel has such low subscribers. Keep up the work My question is those readings which are shown are static or when ac is turned on
Thank you for that awesome comment and the view. The readings shown on this video are with the AC on, engine running. Static pressure is a very good indicator of the level of charge.
hi-side sat temp. was 130F(200psi) Line was 110F lowside sat temp was 32F(30psi) Line was 70F . so that means my subcool is 20F and my superheat is 38F. so that means im undercharged that my ac cycles on and off every 30 seconds? even tho my vent temp was 41F on low speed and non circulate air, on a 95F day still short cycles every 15-30 seconds. some tech believe that is normal for honda/acura BUT theres no way this is normal at idle or even while driving. do you think that the pressure switch is bad or the thermal protect sensor is bad?
Thank you for the question. I have couple of questions for you. Is the pressure switch on the low side? Does the switch have two or three wires? If it is on the low side and it has two wires, some domestic low pressure switches had a screw between the terminals that would you to adjust the cycle range. I doubt Honda has that, you can look. The thermal switch could also cause that problem. If the pressure switch has two wires and is located on the low side. I would try that first. You probable will have some trouble locating a replacement thermal switch. Good Luck.
It sounds like the system is a little low on Freon. Fast forward 3 minutes on this video to verify that the system is low. ua-cam.com/video/C7cx20np7Rs/v-deo.html
Hi. I have a question: I just purchased a gage and it show at low side 36 PSI and 227 high side at 99- degree Fahrenheit in the garage. is a Kia soul 2012 automatic 2.0L is this low in freon? --- The compressor is leaking some oil, dropping when is in use. I'm planning to replace it when summer pass. By the chart you sow it looks like it need freon. Thank you in advance. is cooling good inside.
Hello. Thank you for the view and the question. Here is one of my AC videos (15 in all) that can help to answer your question: Break a Leg / Good Luck : ua-cam.com/video/AaxzV0WMTek/v-deo.html
@@theoldmecanicoshow9004 Thank you. I was looking for this video until now. -- I got another: Elantra 2008, automatic with 176K miles. One can of freon added last year for the first time. -- 91 Degree F in the garage- humidity 20% or less. -- Low side:37 PSI------- High side: 210 PSI -- Static pressure: low side:114, and high side: 120 Compressor never stop, it keeps working, fan working, and cooling very nice inside. How do you see it? Both of my Cars have one Fan.
@@irisbaez1972 Your vehicles probably have "Clutch-less" compressors. The clutch never stops turning. The control of the pistons is done by controlling the angle of the wobble plate. The angle of the wobble plate can go from Full stroke of the pistons to almost zero stroke of the pistons. Bottom line...if it's Cold inside, it's good. Break a Leg as always.
@@theoldmecanicoshow9004 Both on Kia soul and Elantra has Clutch. They are not controlled by any Valve that I see in other Compressors. They don't turn on after I turn the A/C inside the car. What do you think is better with the Kia soul: change the compressor after summer or just leave it until it dies? I have the new one already to be installed. -- Do you think I need more freon on both cases or they are good like that? Both are cooling inside the cars to around 41-42 degree. === I know there are a lot of people asking you, and I really appreciate your reply. Thank you.
@@irisbaez1972 They would fool me at first. It looks like a clutch...but it never turns off. I say leave as long as possible and hopefully it will not fail at an inconvenient time.
Very informative video! I have a 2015 Nissan Rogue, the low side pressure reads over 200psi, this happened after I added 4oz ac lubricant because it appeared low after testing with ac oil analyzer. The first day I added the lubricant the ac worked fine and the pressure read 30 psi the next day it went to 200 psi.
Thank you for the question. The number one reason the low side goes crazy high is that the hand wheels are not completely closed. Both handwheels should remain completely closed while taking the pressure readings. The only time the handwheels are open is when you are moving the refrigerant in or out of the system or adding oil, or pulling a vacuum. Does the AC still blow cold? Make sure te compressor is engaging. I hope that ws some help.
@@theoldmecanicoshow9004 thank you for your response. This morning ambient temp 18 C, the fan was blowing 8 C cold air, low pressure 20 psi, high pressure 125 psi. After 15 min the the low pressure slowly went up to 75 psi and high pressure came down to 100 psi. Fan was blowing 25 C air.
@@shawnahmad It sounds like the system has a problem with refrigerant "Circulation". Either the expansion valve is not metering the flow correctly or the dryer is restricted. If your going to replace the expansion valve , the dryer should also be replaced. Some valves are kind of easy to replace and some are very difficult to replace. Here is a link that should be helpful in finding the location of the valve, ua-cam.com/video/mD0K4ZFiRuk/v-deo.html If the valve is under the hood...kind of Ez. If valve is in the dash...Hard to replace. Good luck.
@@shawnahmad If the system has a Clutch-less AC compressor, it is probably the control solenoid. The hard part is getting the replacement part. The dealer only sells the complete compressor. The regular auto parts does not offer the part. You can get it online. Good luck.
Was having issues with my 88 Ford LTD Crown Victoria, center duct temp will eventually drop to between 40° 45° just feel like the car was cooling off, so put the manifold on it static psig low side was 300+ started it low side dropped to around 45 psig high side 300 I thought oh I'm over charged removed a few oz everything seem fine I could feel the clutch cycle oh I'm too low, was between 85-88 ambient, my suction was 25-30 accumulater iced up, so I added a can of 134a got the psi up to around 40 low 250 high nice puddle from drain, so with that said I'm thinking my fan clutch is slipping
Thank you for the question. 1988 means R12. I am pretty sure the vehicle has been converted over to R 134a. A couple of things about converting; Ester (Polyester) oil is very important to use. Also, the system should be charged with 20% LESS refrigerant (trust me on that one). Converted vehicles do not cool as well if the vehicle is not moving. 45 degrees is good for vent temp. I hope that helps. And yes. you should change the fan clutch.
@@theoldmecanicoshow9004 it was converted before I bought there's a few things I would have done, ie flush, new accumulater, tube pag oil, but I successfully added a dealer installed air in my 67 Ford convertible, new TXV, dryer, new compressor(york) blows 45-40 all day
@@ericheld4382 Looks like your a Ford guy. FORD First On Race Day. I use to be a Chevy guy (use to be) Gm has gone way done on quality. I use to be Anti-Asian (use to be) Today I praise Toyota and bash Chevy. WOW, what a switch-a-roo.
Thank you for the question. Let the AC be off for a long time (over night). Connect the gauges. Both high and low should read about the temp of the day. For example: If it 85 degrees, the psi's should be bout 85. 70 at 70. If the pressure are good to start with and then the readings are what you say....bad compressor.
Some of the charts are a Google search: R134a pressure chart. Some are of the Mitchell On-Demand reference program (that one requires a subscription) I hope that helps.
I retired before any of those vehicles showed up in my shop. I bet you deal with them all the time when newer vehicles crash and windup in your shop. Thank you for the view and the question.
I got a 2012 ford explorer. I just got it back from the shop from getting the system recharged. They charged me $240. When the vehicle stops the air starts blowing hot and the a/c gages show 87psi low side and 325psi on the high side as soon as the clutch kicks on for a few second the low side 45 psi and high side 445psi
Thank you for the view and what sounds like a the question. If you are in warm to hot temp area, the compressor should stay on most of the time and cycle off once in awhile for maybe 45 seconds. What is the temperature where you are?
@@jda.rebuildz9360 WOW... Any decent shop that was working on the air conditioning should have noticed the cooling fans not coming on. Those cooling fans are not nice to have. They are an essential part of the air conditioning system. I will put a link in this reply so you might be able to test the fans. Good luck. ua-cam.com/video/wurODk_njmo/v-deo.html
Good question. Here in the summer time time in South Texas, when the system is "Normal" (full charge -good compressor- good condenser- good circulation) we go from about 95 static pressure to 40-45. The basic idea is the lower the better. Compressors don't just go from good to bad. They go 1/3 bad-1/4 bad- 1/2 bad and other. I never put the "Maximum" charge so as to get the blue to drop as much as possible. If the blue psi is 40, the evap temp is 40. If the blue psi is 50, the evap temp is 50. (basic idea)
@@theoldmecanicoshow9004 I have a question kind of related to Bilal's question. I have a 2013 Nissan Altima which has not been blowing cool air since I bought it this year. The temp here in Phoenix when I was doing this testing was probably around 105. The static pressure was 100 for both the low and high sides. When I turned the ac on, the low side went to 70 and just stayed there - it din't fluctuate any because I believe the compressor was just staying on the whole time. The high side was 150 when it should have been well above 300. After reading some Nissan forums, many people said to replace the Compressor Control Valve (aka Solenoid) before resorting to changing out the whole compressor. What are your thoughts? I'm getting ready to evacuate and vacuum the system and replace it with this part.
@@PJLaux Hello. Yes the compressor control valve can make the compressor look bad. The main problem is buying the Correct replacement valve. The regular auto parts does not sell the valve and the dealer sells only the complete compressor. I have done it several times on VW's. The VW valve was easy to get to and remove. I don't remember if there was a # number on the valve. With the valve in hand and Amazon offerings, I was able to get the correct replacement. Good luck. (if the compressor has over 100K miles...I would just replace the compressor)
@@PJLaux Yes the compressor control valve can made the compressor look bad. The main problem is getting the replacement part. I have done a few VW valves. The regular after market auto parts does not sell the valve by itself, neither does the dealer. Amazon offers the valve but you have to remove the original one to try to match the offering on Amazon. If the compressor has over 100K miles, I would just change the whole thing...
@@theoldmecanicoshow9004 It is 1998 Honda Accord,I replaced the condenser receiver dryer and two fans radiator and condenser fan.Still the same thing.Now I replaced the compressor.I don't know if that will solve the issue,just replaced today July 29,2022.Thank you.
What if your low side rises to about 30 psi then drops to about 15 then slowly rises back again? This is a new compressor,dryer and orfice tube.The a/c blows cold then not during this
Thank you for the view and the question. If your vehicle is anything in the 2000's it more than likely uses a multi cross flow condenser. If the old compressor had a big break down, it is possible the condenser is restricted. What kind of vehicle is it. How much Freon did you put? What is the High side pressure reading?
@@theoldmecanicoshow9004 Its a 2007 dodge 2500 with a 6.7. The high side dips a little but the low side really fluctuates quite a bit. Thats the only part that wasnt changed
@@EATSLEEPFARM We use to able to "Flush" the condensers clean up until the new design made the passages very tiny small. That condenser is an EZ on to get to and replace. The condenser is restricted and effecting the circulation to the point that it effects the cooling performance. Google multi flow condenser and click on the images to give you an idea how small they are. The new design purpose is to reduce the amount of Freon the vehicle uses to half of what it use to. It use to take four 12 oz. cans to charge a full size pick up. Today, some trucks use less than two 12 oz. cans. Good luck on fixing your vehicle.
I’ve been a mechanic all my life and for 12 years it was my livelihood and had an automotive business for 6 years of that. But back in the 70’s and 80’s we only had books to get info. But nowadays we have the internet and can actually see hands on info. You did a very good job on explaining the ac system and it’s problems that can be somewhat diagnosed by pressures or lack of them. I learned a few things from this. Thanks again.
Thank you for the view and the question. Engine off / AC off...50 psi is normal if the air temp (temp of day) is about 50 degrees. With the engine running, AC on, if the pressures stay at 50 psi, either the compressor clutch is not engaging or compressors with "Clutchless" the angle of the wobble plate is not moving to full stroke. If clutchless, check for AC codes.
Thank you for the view and that positive comment. It was a college class. When COVID came out, we were forced to do on-line training. I put out 15 videos on automotive AC. Here the link to lesson # 1: ua-cam.com/video/Zj_wQdkOHpk/v-deo.html
Not to be petty, but @ 1:50 , any rounding of the numbers is dependent on the number 5. Anything 5-9 you round up. Anything 0-4 you round down. So you rounded in the wrong direction, therefore you can be off by 10 and it will make a difference.
I copied and pasted from the Mitchell Pro Demand software. You can buy a subscription, but it is NOT cheap. (at least $200 per month) The internet has charts available. Search for R134a (or other) pressure charts. Thank you for the question.
I wish I could. I had access only at the College where I taught. The Mitchell Pro Demand is avalable on line,But it cost $$$$$$. Thank you for the view and the request.
Yes yes finally this is precisely what I was looking for. Well presented scenarios with excellent explanations with all the details on why when where to back it up. Thanks for taking the time to do this.
You are very WELCOME, and thank you for such a positive comment. You did see a dozen more of my shows / lessons on AC...? Thank you again.
Finally the professor steps in!!!
wish I saw your video first, probably one of the best video explaining the gauges. thanks
Great video and expert information. You are a wonderful teacher, thank you.
You are Welcome and Thank You for that positive comment.
what a blessing to find this vid! eXcellent, thank YOU!
You are Welcome and thank you for that nice comment.
I apreciate your videos .. ive learned quite a bit and still learning the basics of car air conditioning . Thank you for your videos!! Kudos!!!
You are Welcome. I'm so glad that I can help you and others. I guess I can't stop teaching. Thank you for the view and that positive comment.
Great video and information to a professional teacher. I have learnt so much from you. Thanks to you.
Wow. What an amazing teacher.
Thank you Very much for such a nice comment. Thank you.
Thanks sooo much! Crystal clear!
You are very Welcome and thank you for the views and the comment.
Very informative, thanks!!
Your Welcome...
Helpfully video...well explained. Thank you.
Wonderful lesson, thanks and God bless.
Awesome video I've watched so many, you've done a great job in your explanations!
👍 I APPROVE THIS VIDEO AS BEING 100% TRUE AND ACCURATE !. 👍 You did a lot of work pulling videos and putting it together to make this video you did a very good job if I work to make a video it would be like this.
AC PRO the killer of compressors 😂 👍
Thank you very much for that awesome comment. Thank you.
Great video and explanation. Thank You
Great video, thank you!
You are Welcome and thank you for that positive comment.
BRILLIANT mate.
Plain English.
No, bull shit.
.very well explained.
It's not complicated.
Down to earth explanation.
You are an excellent teacher..
I am impressed.
Awesome ! Thank you for that super positive comment and thank you for the views. I have about 15 videos on automotive AC. I hope you watch a few more. Thank You Again.
Very easy to follow. Wealth of information
Thanks for your time in making video. I found a lot of info to help with my problem.. Keep it up ,Very good stuff..
You are Welcome and thank you for that Positive comment. Thank you.
I have installed a new compressor, drier insert, and expansion valve. The compressor is clutch-less. When the system was charged the low side went to about 65 and the high side only got to about 140. The air never blew cold. It was suggested that I might need a new condenser as well. There was a little over four ounces of oil in the new compressor and only one ounce in the old. So I split the difference and added two ounces back into the new compressor. Thanks for the great video
Hello, the pressures are both off. It's like the compressor is not working to it's full ability. The compressor control solenoid (or what ever your car company calls it) is responsible for controlling the angle of the wobble plate. New compressor come with a new solenoid. It could be the circuit that controls the solenoid. You will need to get a scanner that does Body codes. Check for Trouble codes on the AC. What is static pressure (engine off Ac off) after an hour. The blue psi should be about the temp of the day. Start the engine and turn on the AC. The psi on the blue should drop. If it only drops a little bit, the compressor is not working correctly. I wish I could tell you what is wrong. I would research the internet on your vehicle with that problem. Good luck. And yes, it could be a restricted condenser.
@@theoldmecanicoshow9004 Thanks for the reply. The static pressures have been pretty close to the ambient temperature. You are correct that the low-side does not drop enough when the ac is engaged. If the low-side service port comes before the condenser and is reading too high, and the high-side service port comes after the condenser which is reading much too low then does that support the idea that the condenser is bad/restricted?
@@christophercoburn6376 Yes sir. the condenser passages now a days are SUPER small (that how they reduce the amount of refrigerant used) If the old compressor spilled it's guts, the condenser is restricted.
@@theoldmecanicoshow9004 Thanks so much I'll let you know how things turn out.
@@christophercoburn6376 You are Welcome.
Great video and info. I've got good pressure readings when static and the low and high pressure readings are good when the compressor is running (100 psi on 100 degree day, and 35-40 on low, with 175-200 on the high side), but the compressor is short cycling. It will run for maybe ten seconds before it cuts off the clutch, then comes back on after about ten seconds again. The temps inside the car at the ducts are good when the compressor is running, but it doesn't run long enough for the interior temps to drop on a hot day. I'm not seeing the pressures go out of the above readings when it cuts off the clutch. The compressor and TXV have been recently replaced. Looking at the condenser, the temp at the inlet is about 150 degrees, but about two inches away it has dropped to about 130 degrees, and just then after another few inches, it is about 115 degrees. I was leaning towards replacing the condenser and dryer to ensure that I don't have an internal plug at either of them. Curious if you think this is a reasonable approach, or am I looking at it wrong. Thanks in advance for your help.
100 psi static is a "BASIC" indicator of the amount of charge. 175-200 psi sounds a little low on the charge. See is you can get the "Exact" specs for your vehicle. It does not sound like the condenser is restricted. Don't get carried away put more Freon. Half a can at the most. Good Luck.
This guy is awesome!
Thank You Very much for that Awesome comment. Thank You.
great explaination. terima kasih bosku..
WOW...! You watch my video from the other side of the world. WOW...! Thank you for the view and the comment. Did you see that I have 16 videos on automotive AC. I hope you watch a few more. Thank you.
Great Teacher.Thanks for Sharing
You are Welcome and thank you for the view and that positive comment.
The 2014 Silverado I’m working on in Orlando (late May) has abnormally high suction side(200psi)
High side normal at 150
Compressor running constantly
Hello jakespeed63. About the only time I have seen those kind of readings is when both the handwheels on the manifold gauge set are in the open position / or not fully closed. Both handwheels need to be closed when reading pressures. Was the AC cold?
Great video. Thank you
You are Welcome and Thank You for the view and the comment. Did you notice that I have 14 other videos on AC ?
Thanks this what I'm looking for
You are Welcome.
Excellent video and explanation..
Thank you very much for that that awesome comment.
Thank you, the best guy
Thank you for the view and that awesome comment.
Thank you for the great video!!! Problem I’m having low pressure side reading 100 high side reading 150. 09 Dodge Ram 1500. Condenser, compressor, expansion valve, and evap were replaced 6 months ago. Everything was working fine. About a month ago was not getting any cool air wile idling only when driving for longer periods. Then stopped working blowing cold all together. Condenser/Radiator electric fan went out I replaced it. Hooked gauges up and got these readings today. Any tips on where to start? THANK YOU
The Oil can be kind of tricky to get right. Did you you flush the AC system? How much oil did you add to the replacement compressor. Replacement parts can be very poor in quality / how long they last. I would empty the system/ pull a vacuum and slightly undercharge the system. If the blue psi is still high...the compressor was probably damaged when the condenser fan gave out. Does the 09 Dodge Ram use a clutch-less compressor? If so...the compressor valve can cause those readings. Good luck.
Great video! I need those charts!
Thank you for that kind comment. I got the charts from the internet. Do a search for R 134a pressure charts.
So how do you get the PT chart for each specific vehicle and region? I'm here in Houston TX, but you state that each PT chart is vehicle specific.
Where is the best source to get the charts or what sets of charts do you recommend?
hi World Ford Ranger twin condenser
low side 25--35psi About 28psi is freezing point
high 150--160psi engine idling and engine at 1500rpm
All that on a 110 F day
B4 the 2nd condenser was fitted it was terrible at 290 psi high vents temps were 60F
R12 =R134a high pressures . Modern car makers use small condensers .
Old school R12 was 150--180psi always under all hot climates . Some industrial applications 100-150psi
Thank you young man
You are Welcome.
Wow! Glad I came across this. Very helpful. I do have a situation where my low side is at 35psi and my high side is at 70psi after a fresh recharge. Compressor is running. System is NOT cooling. I'm thinking bad compressor which I could probably replace myself but not sure if there is any other damage to system. Any tips would be greatly appreciated! Thank you again for the great video!
Thank you for that Positive comment. Bad compressor show up on the low side psi. Your low side psi is good. Sounds like you have a restriction somewhere. Watch tis lesson: ua-cam.com/video/mD0K4ZFiRuk/v-deo.html
I hope that helps. Thank you again.
Wow very well explained 2 thumbs up 👍🏼👍🏼
Thank you for that positive comment. Thank you.
@@theoldmecanicoshow9004 my gauges read 45/250 psi amnient temp is 83.inside vents doesnt go below 60 even when I put water on the condenser. I pulled the freon out and pulled a vac the refilled with 25 ounces and same readings. Any advice? Thank you
@@Rekairbrush I hope I can help...each vehicle is different. Some vehicles are colder than others. Here is my suggestions: try to find the factory specs and see what they say (not general specs) make sure the recirculation door works (do you know how to do that?) the oil is important (the correct amount) clean the condenser fins (external cleans) less is better (minimum Freon...not max charge) any problem with the air mix blend door will rob the cold / good luck...what kind of vehicle ?
@@Rekairbrush I hope I can help. Each vehicle is different. Try to get the factory specs (not general specs) Make sure the recirculation door works (do you know how to do that) If the suction line is COLD to the touch and vent is not that good...now you have a problem with the air mix blend door. The oil is important (correct amount) Less is better (not the max charge / minimum charge is better) Good luck...
@@theoldmecanicoshow9004thank you!! I'll look up the specs. What I do know is I replaced the compressor with a used one a couple years ago because of clutch problems and I added the correct pag oil and freon amount. I'll check the recirculating door but have set it open before to no recirculation and still got cold air atleast 50 degrees at vent so I don't think its the issue. I also noticed the low pipe doesn't feel frozen it's cool but not cold and sweating. I was wondering if this could be expansion valve issue? I did pressure wash the condenser to no change.
Thank you again for your expertise!
Does a weak ac compressor always make a noise or can it seem to run fine?
Great stuff Hoss!! Question- I see higher end manifold sets without the sight glass on them like yellow jacket and Mastercool.. Is the sight glass on the manifold needed to pull a vacuum ??? I am hunting a good set and most of them with sight glasses look like El Cheapos.. Thx
The sight glass is a nice "Bell and a Whistle". Everything can be done without the sight glass. I remember my students would get a Kick-Out of seeing the Freon move into the system, that's the only time it's nice to have. Thank you for the question and the view.
Cool :)
Nice video. I have a 2004 chevy impala 3.8 v6 cold air comes out of the passenger side and regular fan air on the driver side and the heater does the exact same thing hot air on the passenger side and regular fan air on the driver side. No one can tell me what it could be. Took it to a couple of mechanics and they dont know. Hope you can give me a good place to start. Been dealing with this for a couple of years. Thank you in advance.
Thank you for that positive comment and the question. Three minutes and ten seconds into this video: ua-cam.com/video/-cuKGAe10QU/v-deo.html
explains the "Dual System. The driver electric actuator needs to be replaced. Some actuators are kind of EZ to replace and some are very difficult. Do a search on you tube for your vehicle on replacing the drivers "Temperature" actuator. Good luck.
Sometimes if fan get two speed and not take second state its mean compressor not make High pressure and not heat radiator.
Great video very informative
Thank you for the view and that positive comment.
@@theoldmecanicoshow9004 excellent teacher. Got my subscription 👍🏻
Amazing
your video is great.
i have a question, so i have a 2006 acura tsx i changed the cabin filter and condenser 3 months ago. recently it started to short cycle when driving above 3000 rpm non stop. at idle it does not short cycle from a cold start only after i driven it, or after the pressure stabilizes. i had the system evac and recharged, it blows cold at idle, shop noticed the low side drop to 12psi when i rev it to 3k rpm and suggested to change compressor so i did. i got new compressor installed and 16oz of new freon, no more short cycling at idle or driving BUT does not seem to get as cold as the old compressor. im out of ideas
The lower the blue pressure goes, the better the compressor is, and when the system is slightly undercharged, the colder it is. Vent temperature is determined by the blue pressure. After market compressors, and rebuilt are sometimes not as good as the factory compressor. It is very EZ to overcharge the system now a days. More Freon is not better, in fact I always put the minimum charge in the system. Have the pressures checked. If the low side is not in specs, have a little bit of Freon removed. Thank you for the comment. Good Luck.
@@theoldmecanicoshow9004 thank you for taking the time to replay to my question. i understand and it makes sense except for the part that when the low side gets lower the better the compressor is?
do you know what is the temperature differential one should except on a good working AC system. for example if its 107F outside there should be a 40 degree difference out the vents? so it would be 67F at idle with car being in the sun all day window up non air circulating. I know house AC good system has a 15-20 degree delta from outside temperature.
Do you know if one can charge the car ac system using subcool and superheat. for example if subcool temperature is high than your superheat than your overcharged the system. if your subcool is lower than your superheat than your system is undercharged.?
today i user a digital temperature because i didn't have a metal one. 30min driving in 106F weather with windows up and air on recirculate my temperature out the center vent was 46F.
@@joeydelmarsjr.646 46F is excellent when outside temp is over 100 degrees. It take time (over 5 minutes) to start to make the inside of the vehicle comfortable.
Had bad compressor, clutch not coming on. Replaced it and charged back to specs on the r134a. I have started the truck and then after 15-20 seconds the high hose from condenser to ac compressor cracked . What will that cause? to crack the high side hose? Plugged condenser? maybe ... restriction in the high side ?, or... thanks for the video.
Yes, more than likely plugged condenser. Starting in about the year 2000, the new style condenser have "Tiny" passages. The tiny passages allow for the manufactures to reduce the charge amount in half. If your bad compressor puked some of it's guts, the condenser is plugged. Thank you for the view and the question. Break a leg / Good Luck my you tube friend.
@@theoldmecanicoshow9004 Thanks for reply. I have order all new parts and waiting to arrive. Will see what happens after they are replaced. Have a nice one.
Great video; one thing I missed. Do you read the gauges when the AC is running? Or when it is off?
Thank you for the view, that positive comment, and the question. All the pressure shown are with the engine on and AC on.
Wondering if you can provide some insight...so after some repairs my truck's a/c cooled pretty well on a hot day, although it took a while to get it down to that temperature each time I drove it. A month and a half later it suddenly started not being able to get below 60 degrees on a hot day. Here are the repairs I've had done in the past couple months:
-Leaky A/C Evaporator was changed out, and since that was the only leaking part in the system, there's no chance of a leak or air getting into the system...refrigerant levels also haven't gone down so that confirms the system is sealed
-My high side line and orifice tube got changed out and so it'd doubtful at best that anything is wrong there
-The fan clutch got replaced, the condenser has no holes in it and the airflow is proven to be more than adequate, so that can't be the issue
-The refrigerant levels were appropriate for the system, but the pressures were both a bit high. I also noticed the condenser was pretty warm when I drove it back to the shop after test driving it today with the new fan clutch.
I can only fear that the compressor is starting to fail or there's a block in the system somewhere. The only thing is, where would a block come from suddenly other than the compressor beginning to come apart internally? What do you think is causing this? I've been plagued with 13 years of one A/C problem after another with this truck and I just want to get it resolved. I'm gonna follow up with the shop next week but they weren't sure what was going on today with it.
Thank you for the question and the view. Works... Does not work....AND KIND OF WORKS. The compressor is a big player that Kind-of-works. When the compressor "Weak" the low side is too high and the high side is normal to low. You say both high and low pressures are too high. You said the condenser feels warm to hot. The passages on late model condensers are very very small. They get restricted and that effects the cooling of the AC. Today, when they do a compressor job, it is recommended to replace the condenser. AC is a luxury. And luxuries cost $$$$. I hope I was of some help. Thank you again.
@@theoldmecanicoshow9004 This was helpful, yes, so thank you! Just to be clear, though, how do condenser passages get blocked being that it's a closed system and stuff can't come into it from the outside? Also, the condenser is original to the truck (2000), so does that count as "late model"?
@@GamingDrummer89 Pieces of the compressor and desiccant from the drier accumulator will restrict the needle size passages. I will attach a link on the next answer.
Start watching at 17:06 seconds and watch about two minutes ua-cam.com/video/XGBAxSDTIoU/v-deo.html
@@theoldmecanicoshow9004 Forgot to mention...my accumulator was changed out along with the orifice tube, so how could the desiccant bag have failed already? Or can a compressor have small pieces coming off inside even if it's not running weakly (like you said it wasn't since the pressures are high)? Does that mean the compressor is on its way out?
I have a Honda with pressure readings of 125 psi on the high side and the gauge is pegged as high as it will go on the low side. Ambient temperature 80 F. I’ve never seen anyone showing these gauge pressures in their demonstrations. Compressor probably shot or bad condenser. What do you think?
Thank you for the question and the view. Either the compressor is not engaged / the handwheels on the gauges are open / or the compressor is completely worn out...like Old Mecanico
On my combine. I replaced the TXV. I'm getting 250 on high but 10 on low. Around 100 degrees F. What could be the issue. I get about 65 degree air in the cab.
Half the time the Aftermarket replacement parts don't work as well as the factory part. Also make use you added the correct amount of Freon. I always charge the Minimum amount/ not the maximum amount. (less is better)
I have been looking everywhere for the gauge readings pressure for normal and defects. Do you know where i can find them
There are two types of gauge reading charts. Generic and specific. Both of these were used on my video. Both came from the Mitchell Pro Demand reference software we use at the college where I taught. Each motor company is different, very different. Some motor companies give you every spec you want and need, and some other motor companies give you NOTHING ! The Asian companies are usually the best / American co. are OK / Euro's are the worst. All of my experience comes from the Pro Demand. I can only guess that the Euro's want you to purchase their manuals and I guess the specs are there. The best specs are the ones that include the changes with ambient temp and humility. The Pro Demand is not cheap. (several $1000) And you are not guaranteed to have all the specs you need for the different vehicles. To answer your question...there is not one source that will provide you all the specs you need. Each motor co. wants you to purchase their manuals. Thank you for the view and the question. Did you notice that I have 15 videos on automotive AC lessons?
Its a shame that this channel has such low subscribers. Keep up the work
My question is those readings which are shown are static or when ac is turned on
Thank you for that awesome comment and the view. The readings shown on this video are with the AC on, engine running. Static pressure is a very good indicator of the level of charge.
I use prodemand too
hi-side sat temp. was 130F(200psi) Line was 110F lowside sat temp was 32F(30psi) Line was 70F . so that means my subcool is 20F and my superheat is 38F. so that means im undercharged that my ac cycles on and off every 30 seconds? even tho my vent temp was 41F on low speed and non circulate air, on a 95F day
still short cycles every 15-30 seconds. some tech believe that is normal for honda/acura BUT theres no way this is normal at idle or even while driving.
do you think that the pressure switch is bad or the thermal protect sensor is bad?
Thank you for the question. I have couple of questions for you. Is the pressure switch on the low side? Does the switch have two or three wires? If it is on the low side and it has two wires, some domestic low pressure switches had a screw between the terminals that would you to adjust the cycle range. I doubt Honda has that, you can look. The thermal switch could also cause that problem. If the pressure switch has two wires and is located on the low side. I would try that first. You probable will have some trouble locating a replacement thermal switch. Good Luck.
Thank you sir
You are Welcome.
2004 silverado. Low side 30 psi high side 175 psi. Outdoor temperature about 90 in New Mexico. Duct temperature about 65. Is that normal?
It sounds like the system is a little low on Freon. Fast forward 3 minutes on this video to verify that the system is low. ua-cam.com/video/C7cx20np7Rs/v-deo.html
Hi. I have a question: I just purchased a gage and it show at low side 36 PSI and 227 high side at 99- degree Fahrenheit in the garage. is a Kia soul 2012 automatic 2.0L is this low in freon?
--- The compressor is leaking some oil, dropping when is in use. I'm planning to replace it when summer pass. By the chart you sow it looks like it need freon. Thank you in advance. is cooling good inside.
Hello. Thank you for the view and the question. Here is one of my AC videos (15 in all) that can help to answer your question: Break a Leg / Good Luck : ua-cam.com/video/AaxzV0WMTek/v-deo.html
@@theoldmecanicoshow9004 Thank you. I was looking for this video until now.
-- I got another: Elantra 2008, automatic with 176K miles. One can of freon added last year for the first time.
-- 91 Degree F in the garage- humidity 20% or less.
-- Low side:37 PSI------- High side: 210 PSI
-- Static pressure: low side:114, and high side: 120
Compressor never stop, it keeps working, fan working, and cooling very nice inside. How do you see it? Both of my Cars have one Fan.
@@irisbaez1972 Your vehicles probably have "Clutch-less" compressors. The clutch never stops turning. The control of the pistons is done by controlling the angle of the wobble plate. The angle of the wobble plate can go from Full stroke of the pistons to almost zero stroke of the pistons. Bottom line...if it's Cold inside, it's good. Break a Leg as always.
@@theoldmecanicoshow9004 Both on Kia soul and Elantra has Clutch. They are not controlled by any Valve that I see in other Compressors. They don't turn on after I turn the A/C inside the car. What do you think is better with the Kia soul: change the compressor after summer or just leave it until it dies? I have the new one already to be installed.
-- Do you think I need more freon on both cases or they are good like that? Both are cooling inside the cars to around 41-42 degree.
=== I know there are a lot of people asking you, and I really appreciate your reply. Thank you.
@@irisbaez1972 They would fool me at first. It looks like a clutch...but it never turns off. I say leave as long as possible and hopefully it will not fail at an inconvenient time.
Very informative video! I have a 2015 Nissan Rogue, the low side pressure reads over 200psi, this happened after I added 4oz ac lubricant because it appeared low after testing with ac oil analyzer. The first day I added the lubricant the ac worked fine and the pressure read 30 psi the next day it went to 200 psi.
Thank you for the question. The number one reason the low side goes crazy high is that the hand wheels are not completely closed. Both handwheels should remain completely closed while taking the pressure readings. The only time the handwheels are open is when you are moving the refrigerant in or out of the system or adding oil, or pulling a vacuum. Does the AC still blow cold? Make sure te compressor is engaging. I hope that ws some help.
@@theoldmecanicoshow9004 thank you for your response. This morning ambient temp 18 C, the fan was blowing 8 C cold air, low pressure 20 psi, high pressure 125 psi. After 15 min the the low pressure slowly went up to 75 psi and high pressure came down to 100 psi. Fan was blowing 25 C air.
@@shawnahmad It sounds like the system has a problem with refrigerant "Circulation". Either the expansion valve is not metering the flow correctly or the dryer is restricted. If your going to replace the expansion valve , the dryer should also be replaced. Some valves are kind of easy to replace and some are very difficult to replace. Here is a link that should be helpful in finding the location of the valve, ua-cam.com/video/mD0K4ZFiRuk/v-deo.html
If the valve is under the hood...kind of Ez. If valve is in the dash...Hard to replace. Good luck.
@@shawnahmad If the system has a Clutch-less AC compressor, it is probably the control solenoid. The hard part is getting the replacement part. The dealer only sells the complete compressor. The regular auto parts does not offer the part. You can get it online. Good luck.
Was having issues with my 88 Ford LTD Crown Victoria, center duct temp will eventually drop to between 40° 45° just feel like the car was cooling off, so put the manifold on it static psig low side was 300+ started it low side dropped to around 45 psig high side 300 I thought oh I'm over charged removed a few oz everything seem fine I could feel the clutch cycle oh I'm too low, was between 85-88 ambient, my suction was 25-30 accumulater iced up, so I added a can of 134a got the psi up to around 40 low 250 high nice puddle from drain, so with that said I'm thinking my fan clutch is slipping
Thank you for the question. 1988 means R12. I am pretty sure the vehicle has been converted over to R 134a. A couple of things about converting; Ester (Polyester) oil is very important to use. Also, the system should be charged with 20% LESS refrigerant (trust me on that one). Converted vehicles do not cool as well if the vehicle is not moving. 45 degrees is good for vent temp. I hope that helps. And yes. you should change the fan clutch.
@@theoldmecanicoshow9004 it was converted before I bought there's a few things I would have done, ie flush, new accumulater, tube pag oil, but I successfully added a dealer installed air in my 67 Ford convertible, new TXV, dryer, new compressor(york) blows 45-40 all day
@@ericheld4382 Looks like your a Ford guy. FORD First On Race Day. I use to be a Chevy guy (use to be) Gm has gone way done on quality. I use to be Anti-Asian (use to be) Today I praise Toyota and bash Chevy. WOW, what a switch-a-roo.
Good job
Thank You for the view and that positive comment.
👍👍
Thank you for the views and the thumbs-up.
Mine is 32 and 225 on hi, summer here in miami 96f what is wrong ? Could you please help me
Hello sir, I have a question, I have one car that reads on low side 35 psi and high side 50, what coil cause that ?
Thank you for the question. Let the AC be off for a long time (over night). Connect the gauges. Both high and low should read about the temp of the day. For example: If it 85 degrees, the psi's should be bout 85. 70 at 70. If the pressure are good to start with and then the readings are what you say....bad compressor.
@@theoldmecanicoshow9004 thank you for your reply sir I appreciate it, I’ll check that
What's the web site for those charts
Some of the charts are a Google search: R134a pressure chart. Some are of the Mitchell On-Demand reference program (that one requires a subscription) I hope that helps.
Mr. Sánchez… anything on 1234yf?
I retired before any of those vehicles showed up in my shop. I bet you deal with them all the time when newer vehicles crash and windup in your shop. Thank you for the view and the question.
3:06 faulty ITS NOT A ATMOSFERE TEMP its system temperature. systwm can heated from car engine
I got a 2012 ford explorer. I just got it back from the shop from getting the system recharged. They charged me $240. When the vehicle stops the air starts blowing hot and the a/c gages show 87psi low side and 325psi on the high side as soon as the clutch kicks on for a few second the low side 45 psi and high side 445psi
Thank you for the view and what sounds like a the question. If you are in warm to hot temp area, the compressor should stay on most of the time and cycle off once in awhile for maybe 45 seconds. What is the temperature where you are?
I am i. Northern California so right now the time is 10:30 and its 90 degrees out. Also i noticed the cooling fans aren’t kicking on
@@jda.rebuildz9360 WOW... Any decent shop that was working on the air conditioning should have noticed the cooling fans not coming on. Those cooling fans are not nice to have. They are an essential part of the air conditioning system. I will put a link in this reply so you might be able to test the fans. Good luck. ua-cam.com/video/wurODk_njmo/v-deo.html
i have question when compressor engages how much pressure drop should be seen at low side.?
Good question. Here in the summer time time in South Texas, when the system is "Normal" (full charge -good compressor- good condenser- good circulation) we go from about 95 static pressure to 40-45. The basic idea is the lower the better. Compressors don't just go from good to bad. They go 1/3 bad-1/4 bad- 1/2 bad and other. I never put the "Maximum" charge so as to get the blue to drop as much as possible. If the blue psi is 40, the evap temp is 40. If the blue psi is 50, the evap temp is 50. (basic idea)
@@theoldmecanicoshow9004 I have a question kind of related to Bilal's question. I have a 2013 Nissan Altima which has not been blowing cool air since I bought it this year. The temp here in Phoenix when I was doing this testing was probably around 105. The static pressure was 100 for both the low and high sides. When I turned the ac on, the low side went to 70 and just stayed there - it din't fluctuate any because I believe the compressor was just staying on the whole time. The high side was 150 when it should have been well above 300. After reading some Nissan forums, many people said to replace the Compressor Control Valve (aka Solenoid) before resorting to changing out the whole compressor. What are your thoughts? I'm getting ready to evacuate and vacuum the system and replace it with this part.
@@PJLaux Hello. Yes the compressor control valve can make the compressor look bad. The main problem is buying the Correct replacement valve. The regular auto parts does not sell the valve and the dealer sells only the complete compressor. I have done it several times on VW's. The VW valve was easy to get to and remove. I don't remember if there was a # number on the valve. With the valve in hand and Amazon offerings, I was able to get the correct replacement. Good luck. (if the compressor has over 100K miles...I would just replace the compressor)
@@PJLaux Yes the compressor control valve can made the compressor look bad. The main problem is getting the replacement part. I have done a few VW valves. The regular after market auto parts does not sell the valve by itself, neither does the dealer. Amazon offers the valve but you have to remove the original one to try to match the offering on Amazon. If the compressor has over 100K miles, I would just change the whole thing...
@@theoldmecanicoshow9004 Thanks, I know where I can get the part online.
I am having an intermittent lost of cooling especially on a 100 degree weather,It comes on and off in the freeway driving.
Thank you for the question. What type of vehicle is it? Year / make / model ? Also thank you for the view.
@@theoldmecanicoshow9004 It is 1998 Honda Accord,I replaced the condenser receiver dryer and two fans radiator and condenser fan.Still the same thing.Now I replaced the compressor.I don't know if that will solve the issue,just replaced today July 29,2022.Thank you.
@@efrensaclolo7021 Let us know what happens. Thank you for the comment.
What if your low side rises to about 30 psi then drops to about 15 then slowly rises back again? This is a new compressor,dryer and orfice tube.The a/c blows cold then not during this
Thank you for the view and the question. If your vehicle is anything in the 2000's it more than likely uses a multi cross flow condenser. If the old compressor had a big break down, it is possible the condenser is restricted. What kind of vehicle is it. How much Freon did you put? What is the High side pressure reading?
@@theoldmecanicoshow9004 Its a 2007 dodge 2500 with a 6.7. The high side dips a little but the low side really fluctuates quite a bit. Thats the only part that wasnt changed
@@EATSLEEPFARM We use to able to "Flush" the condensers clean up until the new design made the passages very tiny small. That condenser is an EZ on to get to and replace. The condenser is restricted and effecting the circulation to the point that it effects the cooling performance. Google multi flow condenser and click on the images to give you an idea how small they are. The new design purpose is to reduce the amount of Freon the vehicle uses to half of what it use to. It use to take four 12 oz. cans to charge a full size pick up. Today, some trucks use less than two 12 oz. cans. Good luck on fixing your vehicle.
icemancooling.files.wordpress.com/2011/03/condsection.jpg
You have the one on the right. The left is from the 80's
Verry good
Thank you for that nice comment and the view.
Good video
Thank you for that good comment.
I’ve been a mechanic all my life and for 12 years it was my livelihood and had an automotive business for 6 years of that. But back in the 70’s and 80’s we only had books to get info. But nowadays we have the internet and can actually see hands on info. You did a very good job on explaining the ac system and it’s problems that can be somewhat diagnosed by pressures or lack of them. I learned a few things from this. Thanks again.
@@dennisgeroux4483 You are very Welcome and Thank you for that Positive comment.
@@dennisgeroux4483 You are Welcome and thank you for that awesome comment. Thank you.
What if both gauge pressures stay the same? 50psi
Thank you for the view and the question. Engine off / AC off...50 psi is normal if the air temp (temp of day) is about 50 degrees. With the engine running, AC on, if the pressures stay at 50 psi, either the compressor clutch is not engaging or compressors with "Clutchless" the angle of the wobble plate is not moving to full stroke. If clutchless, check for AC codes.
Have you thought of impersonating Michio Kaku?
WOW...that's a surprise to read. Thank you for the views and the special comment.
great video... could be a college class
Thank you for the view and that positive comment. It was a college class. When COVID came out, we were forced to do on-line training. I put out 15 videos on automotive AC. Here the link to lesson # 1: ua-cam.com/video/Zj_wQdkOHpk/v-deo.html
@@theoldmecanicoshow9004 I'll watch them all. I'm a DIY but very much interested in learning
Not to be petty, but @ 1:50 , any rounding of the numbers is dependent on the number 5. Anything 5-9 you round up. Anything 0-4 you round down. So you rounded in the wrong direction, therefore you can be off by 10 and it will make a difference.
Thanks , how can i get this book ?
I copied and pasted from the Mitchell Pro Demand software. You can buy a subscription, but it is NOT cheap. (at least $200 per month) The internet has charts available. Search for R134a (or other) pressure charts. Thank you for the question.
@@theoldmecanicoshow9004
Thanks 🌹
@@tarekelbiyaly7073 You are Welcome / De Nada.
Can i get the link pdf?
I wish I could. I had access only at the College where I taught. The Mitchell Pro Demand is avalable on line,But it cost $$$$$$. Thank you for the view and the request.
El sistema de un carro y un tractor es el mismo seńor mecánico viejon
Gracias por la vista y el comentario. Y sí, está en lo cierto acerca de que los dos sistemas son iguales. Gracias de nuevo.
@@theoldmecanicoshow9004 gracias ah ud por sus videos...buen día.
@@tochyromero9926
Igualmente
Algorithm boost.