[Yellowb1rd]

Fellas,

I finally have a good reason to use my US General Leakdown tester that I purchased a couple of years ago. I've been attempting to perform a leakdown test on a spare S4 motor that I acquired to replace the one currently in my 89. I know that I'm at TDC on every cylinder I've checked (so far 1-4), and every single one of them reads 40 to 60 percent leakdown.

I even checked cylinders 5-8 on the one in the car (which I know are good), and I'm getting very similar leakdown measurements. This just cant be right, and I'm questioning the accuracy of the tester, but I don't see any widespread issues with this specific unit when doing an internet search.

I zero out the leakdown gauge (on the right), and the pressure reads about 15 PSI on the pressure gauge (on the left), and THEN I connect it to the hose that is screwed into the cylinder. That's the correct procedure as far as I know.

The replacement motor is still on the pallet, so it's painfully simple to get access to just about anything on the motor quickly. I have the valve covers off, so it's pretty easy to locate TDC based on intake exhaust valves position (both closed) in relation to the piston (just a tick past the topmost position of piston travel, when it starts to drop again). I am using a breaker bar to manually turn the crank to get the pistons to TDC.

Has anyone ever used the US General tester and experienced similar results? I want to get accurate leakdown numbers before throwing this motor into the car, but again, I question the accuracy of this tester.

US General Model number 94190