Newbe 931a2 ctis

[Two Stroke Madness]

The military GL site that I bought my m817 at had a bunch of m923a2 trucks, and everyone of them had flat tires. CTIS sucks!!!

 

[ghitch75]

The military GL site that I bought my m817 at had a bunch of m923a2 trucks, and everyone of them had flat tires. CTIS sucks!!!

My truck had 2 flats and it was the o-rings in the rims...had nothing to do with the CTIS .......CTIS in mine work flawlessly....so they all don't suck.....

 

[Suprman]

The m939a2 system is first gen and requires the proper maintenance to be reliable. Improperly sealed o rings or old leaky wheel valves cause flat tires. Not the system itself. Moisture gets into the wheels because the air dryers arent properly serviced and its all down hill from there. The system works better on the lmtvs. I believe units get the rim/tire/valve complete from the tire shop and swap as a whole sending the original back to the tire shop.

 

[gunsgreg]

Mine just had leaking o-ring in wheel. Seems the more I driven it the better it's worked. As others have said make sure your air supply is dry...

 

[Desertshark]

Well I hope I have eliminated the air dryer as an issue . I just replaced the air dryer with a new pur airdryer.

 

[Two Stroke Madness]

My truck had 2 flats and it was the o-rings in the rims...had nothing to do with the CTIS .......CTIS in mine work flawlessly....so they all don't suck.....

But you were able to work on the truck and fix it. Imagine having two flat tires on the road and not being able to do that. What are the words that would come from your mouth? "CTIS sucks!!!"

 

[Andyrv6av8r]

It does the pressure check and then a quick vent out the release valves. A leak is detected. Put your hand on each of the rear wheel valves. They are pressure held on a stem coming out of the hub. The bracket dosnt do much for them. Centrifugal force pulls them off the stem and you have an air leak. But its hard to tell by just looking at it.

I just had 5 blinking lights from this happening to me Friday. Exactly as described. Check your wheel valves closely.

 

[jcollings]

I recently purchased a M923a2.
Ctis seems to be working, although still waiting for papers.
Any recommendations keep it or delete it.

Thanks

 

[Desertshark]

I finally got mine working.... but as a precautions I would carry some valve cores an air hose .... just incase it ever does decide to quit on you. But that's my .02

 

[jcollings]

Would you know anything about pulling a wheel off? what do you disconnected CTIS valve on wheel and the wheel comes off then? And with that disconnected is the system free to purge air out if you're underway way or is there a check valve.

Thanks

 

[Suprman]

You wont be driving with a wheel off. You can unplug the controller and the cab valve wont do anything.

 

[jcollings]

Got it I was referring to changing a spare tire situation. As that valve is mounted on the wheel/ hub it looks like it's just unthreads and then you can replace it on the new one

 

[Suprman]

Just take it off the wheel you are
replacing and put on the new. Good to have a generic o ring kit and make sure the hand tools you have fit the fittings. The rear wheel valve nut coming off the hub stem if you have that style needs a small
adj wrench with a wide mouth.

 

[jcollings]

So nut coming off hub there's a o-ring in that area? Any torque spec? Or snug an check for leaks.

Thanks

 

[jcollings]

Oh you also said unplug controler got that but cab valve?

Thanks

 

[Suprman]

Its a friction fitting on the rear hub stem. Nut compresses a big rubber piece. Its a bad design.

 

[jcollings]

Is the rubber a available repacement part?

Thanks

 

[Suprman]

They are around. The valve housing is aluminum easy to strip the threads. Rubber piece lasts pretty well. You should take a front and rear assembly apart and put it back together to get an idea what you are dealing with.

 

[jcollings]

Look at TMs and look at exploded view best bet right?

Thanks

 

[Suprman]

Get hands dirty take it apart and put it back together. On the side of the road isnt the place to
learn. Its not hard to do. Be brave.