[Richard]

Jim,

Here is a hand drawn diagram of the front setup. Here are a couple of key points to keep in mind when understanding how the logic works. First, and this is a tricky one. The supply air feeds the height control valve (HCV), the hcv is piped to the six pack, and when the travel solenoids are open the hcv is then connected to the air tanks that feed the air bags. The outlet of the single hcv in the front is teed to merge the air pressure of both sides. That allows the front of the coach to float side to side when in travel mode. The back air bags are not piped that way, so when in travel mode the rear hcv's control the side to side height.

Second, when in level mode, the hcv is now isolated from the air bags. A second supply line to the six pack allows you to inflate the left or right side via the up solenoids. And correspondingly, deflate the left or right side. If the travel solenoids did not isolate the hcv this side to side leveling would not be possible since the left and right bags are teed together at the hcv.

This is an important concept to get. IF, and if the electronics that control the solenoids fail, then you could tie the air lines from the hcv to the air lines leaving the sixpack together with a simple plumbing connection and have the coach return to travel height.

   

Call me at 817 223 2056 if you would like.