My M923A2 wont build air pressure past 30-40 PSI in Primary/Secondary air tanks??

[dilligaf13]

It's pretty much a plug and play replacement. Check the TMs for torque specs on the mounting bolts. If I remember correctly there's a thin gasket that mounts between the compressor and block you'll more than likely need to replace. Other than that it's a pretty strait forward replacement. The second set of hands will be useful because the compressor is on the heavy side and mine was a PITA mounting up by myself. Good luck and have fun.

 

[dawico]

So, I ended up getting a new compressor and am going to have another mechanic with me when I go to take it off. For any of you that have changed a compressor before....is there anything in particular I need to look out for or do you need to tighten the bolts to a certain spec when putting the new compressor on.
Never did this before and kind of hesitant about doing it myself.

Just curious why you are replacing it. Too much hassle to rebuild it or did you see something that you didn't like while in there? Tired of messing with it maybe?

 

[Oldworldtenacity]

Just curious why you are replacing it. Too much hassle to rebuild it or did you see something that you didn't like while in there? Tired of messing with it maybe?

Yeah tired of messing with it, plus I called the the Compressor place and we basically determined that the compressor has to much carbon built up inside of it that is keeping it from producing enough Air pressure since the air was coming straight out of the compressor quite weak...the guy told me he sees it all the time with these trucks and especially with single cylinder compressors period. He said if I used the truck a lot that he could not guarantee the same thing would not happen again to the new one within 3-4 years.

 

[Oldworldtenacity]

It's pretty much a plug and play replacement. Check the TMs for torque specs on the mounting bolts. If I remember correctly there's a thin gasket that mounts between the compressor and block you'll more than likely need to replace. Other than that it's a pretty strait forward replacement. The second set of hands will be useful because the compressor is on the heavy side and mine was a PITA mounting up by myself. Good luck and have fun.

Ok, thanks and will check the TM for that.

 

[Oldworldtenacity]

It's pretty much a plug and play replacement. Check the TMs for torque specs on the mounting bolts. If I remember correctly there's a thin gasket that mounts between the compressor and block you'll more than likely need to replace. Other than that it's a pretty strait forward replacement. The second set of hands will be useful because the compressor is on the heavy side and mine was a PITA mounting up by myself. Good luck and have fun.

Well, I found all of the troubleshooting techniques for low air pressure in the TM, but could not find anything about replacing compressors or torq specs for anything period...so I dunno lol.

 

[Oldworldtenacity]

Well, I just got the new compressor installed and the truck builds air great...so it was the compressor after all.

However, now it wont stop building air all the up to the max PSI of 150 for both primary and secondary tanks....I had to shut it off. The air dryer never sneezed either.

Any ideas?

We installed a new governor before figuring out it was the compressor too...could that have something to do with it?

 

[MtnSnow]

Sounds like you need to adjust the governor down some

 

[Oldworldtenacity]

Sounds like you need to adjust the governor down some

Ok, yeah I kind of was wondering about that. I just read up in another thread that you posted in about how to adjust the governor and going to attempt it here in a little bit.

 

[Oldworldtenacity]

Sounds like you need to adjust the governor down some

Lol, it would be nice if the plastic cover cap would come off so I could adjust it.

I've broken 2 of the 4 plastic notches on it to get it turned about a 1/2 rotation and pulling with pliers.

The fun continues..never ending

 

[Gunnermac]

The cap unscrews, under it is a threaded rod that turns clockwise and counter clockwise. It has a jam nut on it.See Tm 9-23-209-20-3-2 chapt. 13, 13-36. Left will reduce, right will increase. You want to be between 90 and 105. The TM will give you the procedure.

 

[Oldworldtenacity]

Finally got the cap off and got it adjusted to where it builds up to 130psi in both tanks before stopping...I was satisfied with that.

However, once I start moving down the road..it goes up to about 135-137 psi and stops...but only when moving.

Also, The air dryer never sneezes when sitting and idling(no matter how long) and when you are moving down the road it sneezes every 15-20 seconds like clockwork....plus the sneezes are around 5 seconds long now...which I could rationalize because of building up to a little more air pressure than before, but every 15 seconds??...it never did anything like this before.

 

[dawico]

The cap unscrews, under it is a threaded rod that turns clockwise and counter clockwise. It has a jam nut on it.See Tm 9-23-209-20-3-2 chapt. 13, 13-36. Left will reduce, right will increase. You want to be between 90 and 105. The TM will give you the procedure.

That is too low. You need 120 psi for the CTIS to work properly.

Some guys recommend 135 psi but I don't like to push excess pressure on my old girl. Just a hair above 120psi is where I am at and everything works like it should.

 

[WSm925a2]

I have a similar problem, had truck out the other day, on the way home I noticed air dryer stopped sneezing and I started to lose pressure,luckily I made it home. Anyhow both primary and secondary won't build past 30psi now and the purge valve on air dryer has a constant flow of air from it.. I tried putting my finger in there but air still comes out, it isn't really forceful air but it is steady. Is it my air dryer?

 

[Andyrv6av8r]

I have a similar problem, had truck out the other day, on the way home I noticed air dryer stopped sneezing and I started to lose pressure,luckily I made it home. Anyhow both primary and secondary won't build past 30psi now and the purge valve on air dryer has a constant flow of air from it.. I tried putting my finger in there but air still comes out, it isn't really forceful air but it is steady. Is it my air dryer?

Try removing your expello valve on the dryer and cleaning the gunk out of it. Or better yet, replace the dryer with a new one. You'll have a lot less headaches in the end.

 

[WSm925a2]

Try removing your expello valve on the dryer and cleaning the gunk out of it. Or better yet, replace the dryer with a new one. You'll have a lot less headaches in the end.

Thanks, I ordered and air dryer but I want to make sure I am headed down the right road, waiting a week for parts keeps the truck sitting more than moving..

 

[98G]

Thanks, I ordered and air dryer but I want to make sure I am headed down the right road, waiting a week for parts keeps the truck sitting more than moving..

Sounds like air dryer problem to me. That should fix it. There's probably moisture all through your air system. You may want to chase that too...