[77newell]

I had long wondered where the air for the step slide and pocket doors came from, now I know. Just in front of the supply tank near the drive axle is a valving setup that allows separation of the air for suspension from the air for all the other non-brake uses. Air going to the suspension is routed through the valve connected to the blue tubing and the air for the other uses is routed through red tubing. The red tubing valve has a tee with the 3/8" red tubing coming out of one side and a 1/4" black tubing coming out of the other side. that tubing heads forward to the rear bulkhead of pass-through compartment where it splits at a tee. One side goes to the valve for the slide, the valve is mounted on the same bulkhead. The other side of the tee goes back rearward to the pocket doors.

BTW, those two systems have separate pressure gauges so when both ball valves are shut off you can tell which system has the leak by watching the pressures drop. At least that's how my coach is set up.

Having figured this out, the only thing left is to figure out which ports on the front distribution block where. Someday, perhaps I'll spend a few hours sorting that out just in case I have a future problem to solve.