CTIS: oil in the line

Howdy folks.
It's been a bit since I've posted. I've been neck deep in dismantling, painting, and reassembling. Maybe I should start a build thread?

I'm about 2/3 of the way through painting the chassis, and just started prepping the front end.

In preparation for paint, and because I'm replacing the lines anyway, I started removing the old lines today.

I looked through the TMs, but can't quite figure out where this would be coming from. It's either the in or the out of the CTIS, has oil in it.

I did replace the CTIS seals when I installed ECO hubs... Maybe 500 miles ago.

Any ideas before I take the hub apart again?

Thanks

It is the host labeled #1 in this picture.
View attachment IMG_7038.jpeg

I’m pretty sure that’s the breather line that’s tied into the other side and the axle vent before it runs up behind the cab. I also had a bit of fluid in there but I’m pretty sure it was from overfilling the hub fluid after the EcoHub install.

Yea brake actuate, actuator vent, hub vent and CTIS are the 4 lines. Blow air back into the frame port and see where air comes out. If it is CTIS, air will come out of the CTIS dump valve located to the right of the transmission, and possibly the main CTIS vent port behind the grill. If it is the combined hub axle vent plumbing, air will come out the vent line up behind the cab. The two hub vents are tied together and connect down to the main axle housing right of center(two lines side by side). Then the axle vent line connects to the port right next to it and runs up behind the cab…

Hopefully this helps.

You guys are great!

Started with the axle vent hose...

END OF TASK



The vent at the top of the breather was rusted shut. So the next best breather was the CTIS lines vent. Which performed flawlessly...

I tested air through the cross body line...Thank god that wasn't clogged.. that would be a total PIA.

Off to Hose Fast in the morning.