Air Compressor Leakdown Test

[Wildchild467]

I have been chasing a blowby issue coming out of my slobber tube for a while. I did a compression test on the engine and all of the cylinders read about 340 PSI, which I think is ok...l since I rebuilt the engine with new pistons, sleeves, rings and NOS heads. So I am doubting if the blowby is coming from that. It had blowby before the rebuild and still has it after. Frustrating to say the least.

Anyway, I am curious to see if if there is some way to test my single cylinder compression to determine if the rings are worn out. I was wondering if I could block the exhaust and apply pressure to the intake and see what happens? I could take the belt off and start the engine up but that is a longer process. I am just wondering if anybody did such a test on air compressors (either on a deuce or any other air compressor out there).

 

[Floridianson]

I myself would do the belt thing. Fast than typing and posting for me.

 

[frank8003]

......................did a compression test on the engine and all of the cylinders read about 340 PSI...............

Was that static pressure with valves both closed TDC or rolling pressure, best condition, with the starter?
I need to do this and if any advice please post. What did you make, to use, to check, compression?
Either way just take the belt loose, use 1-13/16 wrench on the compressor back Hex and turn it backwards a bit 'till loose.

 

[Floridianson]

Frank I have the compression tester for Deuce if you need it. I could check on shipping cost.

 

[Wildchild467]

I just gutted an old injector and welded up the high pressure port and used the return port to get pressure readings.

I am wondering how i can do a leak down test of my air compressor though. I didnt know if anybody has done them in the past. Just thinking, how else would you test a compressor to make sure it is not worn out? A good old fashioned compression test on the outlet?

 

[Jeepsinker]

I would plumb in a small air tank with a short piece of line that you know is leaking free. You will also have to plumb in a signal line for the governor. Crank the engine and let it build pressure in the test tank, and see if it bleeds back down through the compressor. If you have no leaks it shouldn't cycle on again, unless the compressor is worn.

 

[Floridianson]

Yea I have a gutted injector but also found what they say was the Military compression tester for the Deuce from Bbay but the box and nothing on it has a NSN #. Sounds like you know you have two ways to go. On your mark get set go.

 

[frank8003]

There was this not long ago
http://www.steelsoldiers.com/showthread.php?142780-NOS-Midland-compressors-for-sale

and at the moment there is one left
This is a get one or be sorry sale

 

[rustystud]

I just gutted an old injector and welded up the high pressure port and used the return port to get pressure readings.

I am wondering how i can do a leak down test of my air compressor though. I didnt know if anybody has done them in the past. Just thinking, how else would you test a compressor to make sure it is not worn out? A good old fashioned compression test on the outlet?

There is a "Air-Compressor" tester. Mostly it consists of a special trap that collects the air discharged and tells you how much oil is leaking and how much air-flow the compressor has.