M9295 air leak/ surge

[tonyosman]

Hello everyone I am new to the site I have a m9295a?
Today I went to go start it and it started fine. I put it in drive and it did not want to go anywhere, so I put it in reverse and it clicked in the gear then went to drive and it was fine. I went to the store turned it off started it back up and the air tanks were empty. I go under it the first set of axles to the front of the rear wheels there is a metal canister that is surging out there and at end of the canister there is a hole that points to the ground. I put my finger over this hole, the surge stops but air pressure builds up quickly and when I take my finger off it shoots all the air out. Does anyone know why it is doing this? It is having a hard time holding pressure over 60 psi before this it was holding pressure at 120 psi no problem this vehicle only has four thousand miles on it it is like new. It is also winter here so I'm not sure if maybe a valve could be stuck open?

 

[wheelspinner]

First, yes the valve is stuck. It comes out rather easily, clean it, grease it a little with the correct grease and put it back together.


You need to fix this before you drive it. That is the air dryer, and the truck's inability to build pressure will make the spring brakes come on when you least expect it. Study up on the air system, you WILL need the knowledge.

Second, capitalization and punctuation is your friend. It makes it much easier to read and understand.

 

[porkysplace]

Your going to be needing these
[h=3]

TM's for the 939 series trucks[/h]And you really need to read this one before operating it . It will save you on some costly repairs .
TM9-2320-272-10.pdf
TM9-2320-272-10 Operations manual for the M939 series trucks. Sept 2004

 

[Swamp Donkey]

http://www.steelsoldiers.com/showthread.php?135608-M925-air-brakes

See my post in the link above.

 

[tonyosman]

Thank you everyone. sorry for the grammar, I was using the talk to text feature on my phone and it does not insert
punctuations.

 

[dawico]

Sounds like the air dryer to me too. Stick something up into the hole and it should break the valve free. It may have some ice in it if it is cold enough.

My understanding is that that is where the dryer kicks out moisture.

 

[Al Harvey]

Welcome from Tennessee. The TMs are great source of information and part numbers.

On a side note, please avoid using "Help" in the thread title unless you are broken down on the side of the road.