Billy, thank you so much for posting this. I was getting 85% with the gauges in the original condition and the motor only had 1500 miles on it. I knew something was not right. After the conversion you showed, all cyls came out to 4-6% loss. SO glad I saw your post. Cheers!
Thanks! This makes this cheap tool actually useful. Mine is the Pittsburgh branding, but looks identical. If it helps anyone, a MKIV VW CV axle bolt fits perfectly to plug the hole left in the tool's block.
Thanks so much for this....Really kind of a crummy set up they have....Testing pressures not high enough...Off to hardware store for a plug...thanks again....
very nice, thank you sir we needed someone to prove this tool is naturally defective and how to modify it to use it in a better manner. great video will be sharing...
I just bought one of these to use on a 235 chevy motor. with both gauges connected, the pressure gauge would only go up to about 7 pounds before the leakage gauge got to zero. Then, when I hooked the hose to the motor, the press gauge would go to zero and the leak gauge would give a different reading between 20 and 80% each time, even on the same cylinder. I switched gauges around and brought the press gauge up to 90 (as high as it would go). it had between a 10 and 20% drop every time. My question in all this is, do you find your gauge to be accurate every time?
I just tore one of these apart today, have only used it ONCE. I ordered some .040 jets on ebay, these are not "FAA spec" but they will be better than what this had. The internal orifice is somewhere around .1--.125, nowhere near the .040 "specd" for one
I was just thinking of doing the same! bought a cheapo a$$ on amazon for 25 bucks, tested it and i ONLY get a variable reading on the 2nd gauge around 25-35 psi, FAR from the 100 psi required! Ill be doing the same, is yours working after the mod? Super frustrated! Be much more reliable to make your own with a regulator and a comp gauge as a 2nd gauge to give you a real time drop from 100 -
I think im starting to understand - the gauges work gauge to gauge, ie the cheapo kits just give readings at a much lower psi, which "works" theoretically - not sure if the 100 psi is a mandatory figure, im sure you could hear 35 psi coming out of a leak.. It makes sense reducing the orifice/jet will increase the psi requires to show a variation between the gauges - but either way you are comparing gauge A with B. Changing the orifice just moves the psi margin -
From manual: Follow manufacturer’s instructions to perform a cylinder leakage test. (Never use high pressure leakage testers, as crankshaft seals may dislodge and leak). .. Should it not be necessary to lower the compressors reguletor for leakdown testing for this safety reason ?
This warning makes no sense. The only way to build up crankcase pressure is to have air bypass the rings. However, with proper crankcase ventilation, there is no pressure build up that could blow out crankshaft seals.
Its from Polaris Sportsman 700 twin 2002 atv manual; 4 stroke 2 cylinder engine. COMPRESSION TEST CONT’D A cylinder leakdown test is the best indication engine condition. Follow manufacturer’s instructions to perform a cylinder leakage test. (Never use high pressure leakage testers, as crankshaft seals may dislodge and leak). Cylinder Leakdown Service Limit 10 % (Inspect for cause if leakage exceeds 10%) Cylinder Compression Standard: 150-170 PSI
I never heard of that engine. It’s obvious that it has a tightly sealed crankcase which allows the air which bypasses the rings to build up internal pressure which will blowout the crank seals. Thus those instructions are specific to that engine. Every engine I worked on had crankcase ventilation that would never allow the pressure to build up.
Thats informative. I´l be aware, if testing on this Polaris atv. Im in rookie level, trying to maintenance my vehicles. I quess you should always fallow the manual first. Maybe I can use compressed air leak tester, but should turn the gauge down on compressor to lower the air pressure psi...Anyways i had all sort of symptoms with polaris...overheating (boiling coolant), oil mixing with coolant, detonation, hard starting, no starting etc, .. I think its time to overhaul the engine.
Hi Billy I read some posts on the interwebs that say you have to have the two gauges to truly judge the differential. Would you mind commenting on that? Just want to make sure the good readings im getting are accurate. Thanks Brett
Hay Stoicokie: Some manufacturers use only a single gauge. In these instruments, the orifice inlet pressure is maintained automatically by the pressure regulator. A single gauge works well as long as leakage flow is much less than regulator flow. Any error in the input pressure will produce a corresponding error in the reading. As a single gauge instrument approaches 100% leakage, the leakage scale error reaches maximum. This may or may not induce significant error, depending on regulator flow and orifice flow. At low and modest leakage percentages, there is little or no difference between single and dual gauges. Simply stated, in a badly leaking cylinder there is more reading error than a cylinder which has little leakage. If you wish, rather than the plug you can get a second 100 lb. gauge and you have a typical two gauge tester. Hope this helps Billy
Billy Lowe that makes perfect sense. My cylinders produced 4-6% leakage across the cylinders so sounds like I'm ok! I didn't have a plug so just swapped the gauges. But I have a plug on order and will redo with the plug. Thanks for taking the time to reply.
Billy Lowe hi Billy sorry for the multiple questions. I read somewhere that if you hook up gauge and then take out hose from the plug hole the gauge should drop to 0 from whatever it was while hooked up. Meaning all lbs should rush out through hose and gauge should read 0 due to no pressure. That's not my experience. When I remove spark plug hose and hook up it does rush out but only down to 70%. Would that make sense with the small hose diameter or should I see a 0 reading? Just want to make sure I'm getting accurate leakage on full open.
I found out through 2 of these now it is totally in-adequate. Would just swapping the 2 dial gauges and ignoring the leak % one net the same result or is the plug necessary?
+Supra sam The problem is the regulator is not accurate at the low pressures of the tester. The second gauge does not give accurate and constant readings .
Hi. Just wonder if you can tell me what the problem is with my engine. cylinder 3 has only around 25 psi. And the rest 160 psi. The engine is tuned up from 150 hp to 280 hp. And the spear plugs is dry and werry white. Hope you can respond. Thanks from Norway.ua-cam.com/video/YlJduTNkIRQ/v-deo.html
put the cylinder at TDC after the intake stroke then lock the engine so it will not turn. Now apply air pressure to the cylinder through the spark plug hole at around 50 lbs per sq in. and listen to find out where the air is leaking. (exhaust, intake, crankcase or cooling system) This is only a guess, but I bet you have a problem with the exhaust valve for that cylinder. Good luck
Billy, thank you so much for posting this. I was getting 85% with the gauges in the original condition and the motor only had 1500 miles on it. I knew something was not right. After the conversion you showed, all cyls came out to 4-6% loss. SO glad I saw your post. Cheers!
John H I'm glad it worked out for you.
Thanks! This makes this cheap tool actually useful. Mine is the Pittsburgh branding, but looks identical. If it helps anyone, a MKIV VW CV axle bolt fits perfectly to plug the hole left in the tool's block.
Thanks so much for this....Really kind of a crummy set up they have....Testing pressures not high enough...Off to hardware store for a plug...thanks again....
very nice, thank you sir we needed someone to prove this tool is naturally defective and how to modify it to use it in a better manner. great video will be sharing...
Nice, these are being sold at clearance prices, and this fix allows for realistic testing pressures. Thankyou
I noticed the back of the gauge's needle is bent up.
That's the nail on the head right there. The second gauge is only rated 10-20 psi.
I just bought one of these to use on a 235 chevy motor. with both gauges connected, the pressure gauge would only go up to about 7 pounds before the leakage gauge got to zero. Then, when I hooked the hose to the motor, the press gauge would go to zero and the leak gauge would give a different reading between 20 and 80% each time, even on the same cylinder. I switched gauges around and brought the press gauge up to 90 (as high as it would go). it had between a 10 and 20% drop every time. My question in all this is, do you find your gauge to be accurate every time?
I just tore one of these apart today, have only used it ONCE. I ordered some .040 jets on ebay, these are not "FAA spec" but they will be better than what this had. The internal orifice is somewhere around .1--.125, nowhere near the .040 "specd" for one
I was just thinking of doing the same! bought a cheapo a$$ on amazon for 25 bucks, tested it and i ONLY get a variable reading on the 2nd gauge around 25-35 psi, FAR from the 100 psi required!
Ill be doing the same, is yours working after the mod? Super frustrated! Be much more reliable to make your own with a regulator and a comp gauge as a 2nd gauge to give you a real time drop from 100 -
I think im starting to understand - the gauges work gauge to gauge, ie the cheapo kits just give readings at a much lower psi, which "works" theoretically - not sure if the 100 psi is a mandatory figure, im sure you could hear 35 psi coming out of a leak..
It makes sense reducing the orifice/jet will increase the psi requires to show a variation between the gauges - but either way you are comparing gauge A with B. Changing the orifice just moves the psi margin -
From manual: Follow manufacturer’s instructions
to perform a cylinder leakage test. (Never use high
pressure leakage testers, as crankshaft seals may
dislodge and leak). .. Should it not be necessary to lower the compressors reguletor for leakdown testing for this safety reason ?
This warning makes no sense. The only way to build up crankcase
pressure is to have air bypass the rings. However, with proper crankcase ventilation,
there is no pressure build up that could blow out crankshaft seals.
Its from Polaris Sportsman 700 twin 2002 atv manual; 4 stroke 2 cylinder engine.
COMPRESSION TEST CONT’D
A cylinder leakdown test is the best indication
engine condition. Follow manufacturer’s instructions
to perform a cylinder leakage test. (Never use high
pressure leakage testers, as crankshaft seals may
dislodge and leak).
Cylinder Leakdown
Service Limit 10 %
(Inspect for cause if leakage exceeds 10%)
Cylinder Compression
Standard: 150-170 PSI
I never heard of that engine. It’s obvious that it has a
tightly sealed crankcase which allows the air which bypasses the rings to build
up internal pressure which will blowout the crank seals. Thus those
instructions are specific to that engine. Every engine I worked on had
crankcase ventilation that would never allow the pressure to build up.
Thats informative. I´l be aware, if testing on this Polaris atv. Im in rookie level, trying to maintenance my vehicles. I quess you should always fallow the manual first. Maybe I can use compressed air leak tester, but should turn the gauge down on compressor to lower the air pressure psi...Anyways i had all sort of symptoms with polaris...overheating (boiling coolant), oil mixing with coolant, detonation, hard starting, no starting etc, .. I think its time to overhaul the engine.
Hi Billy I read some posts on the interwebs that say you have to have the two gauges to truly judge the differential. Would you mind commenting on that? Just want to make sure the good readings im getting are accurate.
Thanks
Brett
Hay Stoicokie: Some manufacturers use only a single gauge. In these instruments, the orifice inlet pressure is maintained automatically by the pressure regulator. A single gauge works well as long as leakage flow is much less than regulator flow. Any error in the input pressure will produce a corresponding error in the reading. As a single gauge instrument approaches 100% leakage, the leakage scale error reaches maximum. This may or may not induce significant error, depending on regulator flow and orifice flow. At low and modest leakage percentages, there is little or no difference between single and dual gauges. Simply stated, in a badly leaking cylinder there is more reading error than a cylinder which has little leakage. If you wish, rather than the plug you can get a second 100 lb. gauge and you have a typical two gauge tester.
Hope this helps
Billy
Billy Lowe that makes perfect sense. My cylinders produced 4-6% leakage across the cylinders so sounds like I'm ok! I didn't have a plug so just swapped the gauges. But I have a plug on order and will redo with the plug. Thanks for taking the time to reply.
Stoicokie: With a leakage of only 4-6% you're in excellent shape and any gauge error is un-readable.
Billy Lowe hi Billy sorry for the multiple questions. I read somewhere that if you hook up gauge and then take out hose from the plug hole the gauge should drop to 0 from whatever it was while hooked up. Meaning all lbs should rush out through hose and gauge should read 0 due to no pressure. That's not my experience. When I remove spark plug hose and hook up it does rush out but only down to 70%. Would that make sense with the small hose diameter or should I see a 0 reading? Just want to make sure I'm getting accurate leakage on full open.
Thanks for the info. The HF regulator is crap. Sent it to a flat 100 psi, let it rip. Easily read the leakdown...
I found out through 2 of these now it is totally in-adequate. Would just swapping the 2 dial gauges and ignoring the leak % one net the same result or is the plug necessary?
+craiggus365
swapping the gauges should work ok too
The second gauge is in 5% increments so just divide the percentage on the second gauge by 5, so 100% on the gauge means 20% leakage
+Supra sam
The problem is the regulator is not accurate at the low pressures of the tester. The second gauge does not give accurate and constant readings .
Brilliant!!!
This tester doesn’t work correctly. Harbor Freight realized this one wasn’t designed right so now they do sell one that works like it should.
Get the otc one
You can't do a proper leak down test with 1 gauge. You need one gauge for input pressure and the other to show the leak PSI, then convert it to %.
Hi. Just wonder if you can tell me what the problem is with my engine. cylinder 3 has only around 25 psi. And the rest 160 psi. The engine is tuned up from 150 hp to 280 hp. And the spear plugs is dry and werry white. Hope you can respond. Thanks from Norway.ua-cam.com/video/YlJduTNkIRQ/v-deo.html
put the cylinder at TDC after the intake stroke then lock the engine so it will not turn. Now apply air pressure to the cylinder through the spark plug hole at around 50 lbs per sq in. and listen to find out where the air is leaking. (exhaust, intake, crankcase or cooling system) This is only a guess, but I bet you have a problem with the exhaust valve for that cylinder. Good luck
Thank you for your respond, Billy. And yes I think I have a big engine problem. Think I have to replace the engine. Have a nice day. :)
Junk