> What is the "leak down test"? I've been meaning to ask for a while but not
> quite got around to it.
I'll explain to the best of my knowledge and abilities. Essentially you
force air into the motor and determine where it leaks out from. The leak
down testing tool has two gauges, one for input air pressure, and one for
the air pressure in the cylinder. (all done while the motor is not in use
of course, and not turning over). You take the ratio of the two to
determine your loss, or snap-on makes one that does all the math for you.
If you're airline is set at 100psi, an you are maintaining 70psi in the
cylinder... you have a 30% loss obviously. The beauty of a leak down test
is you can see or hear where you have a leak. If you have bubbles in the
coolant, your head gasket is shot... if you hear the air hissing out as you
listen to the exhaust, well it's probably going up the exhaust valve guides.
Intake, you can hear the escaping air if you were to open the throttle
plates. And if you still have a 30% loss and it isn't coming from anywhere
else, you can assume rings.
Does that help any?
Kai
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