[Richard]

It’s a wee bit difficult to understand exactly what is going on, since my interpretation is that the problem is not clearly defined. Is the problem, the coach settles when parked? Is the problem the coach does not rise immediately when cranked unless the P brake is released?

One of the hardest concepts to get your head wrapped around is that the air pressure while the coach is parked had NOTHING to do with the coach settling. NOTHING !!!!!

How could that be? Both the HWH systems and the Valid systems isolate the air bags from the coach though either the six pack or individual solenoids on the Valid. Unless those valves are leaking backwards into the air supply then the leak down is between the six pack all the way, and including the air bag. If one understands that it will save a lot of effort at understanding what is going on. The HCV is on the inlet side of the six pack or solenoid valves. Even if it leaks like a sieve, the coach should stay up while parked. The coach air pressure will go to nothing, but the coach should stay up. Forgive me for hammering the point, but MANY have spent futile hours and dollars chasing a settling coach because they did not understand the role of the six pack.

Before I get roasted, it is possible that one of the solenoids is leaking internally or externally and that will cause the coach to settle. It does happen and it’s easy to address with a rebuild kit of the solenoids, but it is not the common cause.

Let’s address the P brake issue, with due respect that there are a number of posts that mention this in far greater detail. So I will present the condensed version. On later year Ridewell suspension coaches that have the parking brake which activates both the drive axle and the tag axle brakes, application of the P brake inhibits the suspension from going up or down. If you look at the suspension design, the swing of the suspension up and down as the coach moves is in opposite direction for the drive and tag axle. Because the P brake locks the tire to the axle, it is not free to rotate as the suspension rotates about its pivot point. The drive tires “want” to rotate in one direction, and the tag tires “want” to rotate in the opposite with this suspension design. The P brake prevents the rotation. You can prove it to yourself by either raising or lowering the coach with the P brake on. When the P brake is released the rear of the coach will jump several inches.

If you have a leaking air bag situation, this will drive you nuts in the middle of the night as the coach tries to settle because you continually get pops and groans as the brakes try to prevent the settling.

And those that have commented that the rear of the coach requires greater than 100 psi of air pressure to raise are absolutely correct. It has to do with the weight of the rear and the diameter of the air bags that Newell specified.