[Richard]

The picture is very helpful.   HWH will be no help, because that is NOT an HWH manifold. There was a short period where Newell was making their own. I believe you have one of those.

Let’s confirm some things before disconnecting air lines. 

Using your picture, I think the travel solenoids are the two on the far right. I think that because they are wired together. Please confirm by key on, travel on, and checking the solenoids to see if they are magnetized. A small steel washer is your friend. 

Keeping this one counterintuitive concept in mind, the six pack is BETWEEN the height control valve and the air bag. That throws many a truck mechanic for a loop. 

In order to approach the problem systematically, the air lines must be identified. The two adjacent to the travel solenoids will originate at the HCV. One top and one bottom. The left side is normally on the top. 

It’s the other four lines that I don’t know about. One pair, top and bottom, should have supply pressure. They would be used to raise the coach when in Level mode. The other pair, top and bottom will go to the air bags. 

This is how I would approach it. You will need an external air compressor and some fitting arrangement to connect to the tubing that you disconnect from the manifold. I would start with the tubing on the upper left. Disconnect from the manifold and pressurize that tubing with the air compressor. If this is indeed the line to the left air bag, then the left rear should start to raise when you pressurize the line. 

I think, and that’s a SWAG, the middle lines, top and bottom are from the supply side. That would be confirmed by disconnecting them and seeing if they air up when you turn on the coach compressor.