M923A2 gear oil leak from CTIS

[MATT]

I'm getting gear oil from a part mounted on the left rear frame. The part seems to be a CTIS "T" that must supply air to the rear tires/rear axle. Is there a check valve somewhere? Anyone come across this?

 

[PSturg66]

More than likely a blown CTIS seal, getting oil at the air dryer yet?

 

[MATT]

Not yet. Where is the CTIS seal?

 

[PSturg66]

In the wheel hubs. My bad I read this quick, the part you are talking about, looks like a valve, yes? Normally when you see 80/90 or gear oil coming out of the QRF or quick release valve, it is a sign of a ctis seal that is allowing air into the diff housing. Most the time, it blows it out of the breather. There is a check valve on the wheel assy, but that is so that the air doesn't leak from the tire back into the system.

Hope this helps.

 

[MATT]

Thanks. I'll take the wheels off and staring pulling things apart.

 

[PSturg66]

Before you tear it down, take off the line on the outside of the wheel assy that supplies the air. See if there is oil there. Do that to all your wheels. Each wheel assy that you find oil at, is where you will find a blown seal.