m939 air system check valve - Steel Soldiers::Military Vehicles Supersite

Bolkbich · 01-15-2012, 23:22

My M932a2 was doing funny things. The air compressor was cycling ,the safety blow off valve on top of the air dryer was popping off with only 100-120lbs of air. I started at the dryer and was going through everything when i came across a check valve inbetween the dryer and the first air tank. It was rusted solid and only letting small amounts of air through. I split the valve cleaned out the rust and freed the rubber check. Fixed all my problems. I checked my other 2 m939's that showed no symptoms and they were rusted solid too. One i could free up , the other broke trying to get it apart. They build air much faster now. Just a heads up , if all 3 of mine were stuck im sure its a common problem.

Stonepicker1 · 01-15-2012, 23:51

You are correct on those check valves going bad. Back in the late 90's we went through all of our M900 series trucks and and replaced most of them.

I will be replacing all of my check valves on my new M923.

YOU GOT TO DRAIN THOSE AIR TANKS.

usmarines72 · 01-15-2012, 23:59

Where can a guy get those check valves?

Stonepicker1 · 01-16-2012, 00:11

Quote:

Originally Posted by usmarines72

Where can a guy get those check valves?

Google "N13526H"

Bolkbich · 01-16-2012, 00:17

I checked a couple of other check valves on the upper tanks they were all ok. It just seemed like the first valve had the condensation sitting in it. Im going to check my local truck parts guy tomorrow. Hope he has them. I hate specialty parts.

usmarines72 · 01-16-2012, 00:59

How many of these check valves do these trucks have. Might as well order enough to replace them all.

Stonepicker1 · 01-16-2012, 01:08

Quote:

Originally Posted by usmarines72

How many of these check valves do these trucks have. Might as well order enough to replace them all.

I think it is three.

wsucougarx · 01-17-2012, 21:14

Bolkbich thanks for the heads up!! Just ordered 4 valves off ebay for $7 each. Also picked up a spare fuel solenoid just in case. Are there any other parts someone should have on hand that are frequent problematic?