leakdown test..am I doing something wrong?
Thread Starter
Pro
Joined: Aug 2005
Posts: 627
Likes: 1
From: Naperville IL
leakdown test..am I doing something wrong?
I just picked up a leakdown tester from harbor freight that has the 0-100psi guage on one side and a percentage loss guage on the other. the thing is when I try to use it the loss guage is always pegged at way below zero unless I back the pressure off to around 15 psi. I can hear air flowing through, so it should read something over zero. I don't see any other adjustments on the guage for calibration other than the regulator either. Am I doing something wrong here or is it just a crappy guage?
Melting Slicks
Joined: Sep 2000
Posts: 2,403
Likes: 416
From: Chester Virginia
the instructions for my unit says:
Postion cylinder at TDC
Turn the regulator **** fully counter-clockwise. then connect shop air, 45-150 to the regulator w/o cylinder hose connected. turn reulator clockwise until leak gage reads zero at the right end of the gage.
Screw cylinder hose into spark plug hole and then connect hose plug end into quickcoupler of tester block. The amount of leakage will now show on the leak gage as a % loss.
Roger
Postion cylinder at TDC
Turn the regulator **** fully counter-clockwise. then connect shop air, 45-150 to the regulator w/o cylinder hose connected. turn reulator clockwise until leak gage reads zero at the right end of the gage.
Screw cylinder hose into spark plug hole and then connect hose plug end into quickcoupler of tester block. The amount of leakage will now show on the leak gage as a % loss.
Roger
Thread Starter
Pro
Joined: Aug 2005
Posts: 627
Likes: 1
From: Naperville IL
I have the distributer cap and valve covers off, so I know I'm at least close to the top of the compression stroke. It's setting the guage before I even hook it up to the engine that doesn't seem right. It seems like the second guage is just very badly calibrated with no way to adjust it.
Thread Starter
Pro
Joined: Aug 2005
Posts: 627
Likes: 1
From: Naperville IL
I would not be surprised at all if that was the problem, but I did do a little searching around the net and got the impression that this guage was at least usable for what it was. Maybe I can go to grainger and pick up a bette pressure guage to replace the %loss guage with something I can adjust.
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Racer
Joined: Sep 2006
Posts: 469
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From: Sandy TX
Melting Slicks
Joined: Sep 2000
Posts: 2,403
Likes: 416
From: Chester Virginia
I believe the % loss is just a pressure gage, but but a dial label showning precentage loss atarting at the max pressure reading of the gage. For you your %loss gage is probably a 0-15 psi gage. As the air flows out of the cylinder you lose prssure due to the air flow. The only difference between a 0-15 and a 0-35, like mine, would be a small amount of accuracy. I would just use what you have.
Roger
Roger