Another CTIS question

[charger53]

I have a 91 M923A2. When I got the truck the CTIS was unplugged at the controller. I plugged it in and all seemed well for about 15 min, then the thing dumped the air in the front tires. It does it every time I plug it in now. I have visually (and by sound) checked for leaks in the system. (havn't had time to do soapy water yet, but I will). I have reset the system several times in accordance with different posts I have searched. I have aired all tires to 70 psi and plugged it in before starting and yet it dumps front tires every time, I have downloaded the CTIS trouble shooter and TM's. I am very mechanically adept, however Honestly I have not had time to do a proper diagnostic. If I run the CTIS long enough it will dump all tires, but will not air anything up. I do have a extremely slow leak somewhere in the left rear (Like 3 weeks to look low). I will do all the proper steps of diagnostics when I have time, however that could be next winter. I was wondering if anyone with some experience may just recognize this and tell me what to fix?

 

[hklvette]

Do you happen to have the P2P program? Its has a pretty good animated diagram of the CTIS system. If you don't have the program, its posted in the 5-ton TMs section.

edit: meant to add that it sounds like your quick release valves are getting stuck. If they keep some pressure in the CTIS system because they're not fully opening, the tires will drain into the wheel valves and out the exhaust valves.

 

[charger53]

I don't, just the standard TM's. I will download it when I get home tonight though.

 

[hklvette]

Well, as luck would have it now that I am bringing the CTIS on my 931A2 back into working order the exhaust valve on the mid-axle is doing the exact thing that you saw and I described. Time to remove and rebuild more parts...

 

[Mike929]

Well, as luck would have it now that I am bringing the CTIS on my 931A2 back into working order the exhaust valve on the mid-axle is doing the exact thing that you saw and I described. Time to remove and rebuild more parts...

Please take pictures if you can and let us know how it goes. I'm thinking purely of myself. I am thinking of getting an 5 ton A2 and it looks like working on the CTIS is a major experience of ownership.

... also, I'm sure there are others that may be able to help and pictures always draw more viewers.

 

[charger53]

Please take pictures if you can and let us know how it goes. I'm thinking purely of myself. I am thinking of getting an 5 ton A2 and it looks like working on the CTIS is a major experience of ownership.

... also, I'm sure there are others that may be able to help and pictures always draw more viewers.

I second pictures. When I get a little time I will be doing the same repair

 

[hklvette]

Please take pictures if you can and let us know how it goes. I'm thinking purely of myself. I am thinking of getting an 5 ton A2 and it looks like working on the CTIS is a major experience of ownership.

... also, I'm sure there are others that may be able to help and pictures always draw more viewers.

I intend to make a thread outlining what it takes to repair the various issues involving CTIS, short of replacing the seals inside the hubs. Its actually a very simple system to repair, but takes time and some machined parts to do it right.