Class problems

[Big Auggie]

My CLASS system isn't holding air pressure. To help isolate the problem I picked up a short bolt and initially installed it where the front shock's supply line enters the compressor. I brought the system up to pressure but it didn't maintain it. Out of curiosity, I plugged the outlet for the rear shock's supply line and put the front shock's line back on the compressor. It still wouldn't maintain pressure. My thinking is either I have leaks in both the front and rear shock systems or the compressor has problems. (I'm leaning towards the compressor).

 

Are the compressors rebuildable?

[Karaboo]

If the system pumps up to pressure, the compressor is doing its job. Sounds like it may be a leak in the valves that control the air. Pull the trunk off, grab a spray bottle of soapy water and check all the air line connections and solenoids. You may as well pull the drier and change out the desiccant (or dry it out) "while you are in there".

If the valves and connections do not leak externally, they may still be leaking by when they are supposed to shut off the air. I don't know if they can be rebuilt, but they should be cleanable.

[Neil86]

Many years ago Yamaha released a service bulletin on the CLASS system.

One issue is a cracked or broken reed valve.....its made of plastic and mounted where the hose from drier connects to the solenoid block.

 

The reed valve acts as the check valve to prevent air leaking back into compressor once compressor shuts off.

Edited February 3, 2015 by Neil86

[Marcarl]

Could very well be that moisture has gotten into the valves. This will corrode the seats and so the valves will not shut off. Carefully take the solenoids apart to do a proper maintenance. If you find the seats are corroded, put some fine steelwool on the end of a small dowel. With a drill spin the steel wool into the seat until it's clean again.