I learned something today that I thought I would share. In my coach, the differential "lock up" air solenoid is located on the firewall above the engine batteries. On some coaches (around the 2003 vintage) the solenoid housing is mounted with the "out" port on the top.
As you go down the road, grit and dust find their way into port and if you ever use the lock-up function the grit falls into the valve body and this can cause a HUGE air leak. (ask me how I know this!)
Check your coach for the housing mounted upside down. (Out port is up). If so, you should clean out the port and then remount the housing with out port on the bottom. (Don't mix up the air lines).
I've always had the thought that one of the reasons for the 6-pack solenoids failing is because of trash cutting the sealing surfaces. But as it's a closed air system that shouldn't happen, but as you've just demonstrated possibly trash is getting in through the exhaust port. Who's gonna be the guinea pig and add an exhaust filter to the 6-pack exhaust?
Don't make me buy another Newell just to prove my theory....
My coach has an exhaust filter on the front six pack installed prior to my ownership. I cant speak for its effectiveness - i recently went through the entire six pack to rebuild and clean out a far amount of build up.
It strikes me as a good idea though - one more tool in maintaining a clean air system.
Since I replaced the original finned air dryer with a Bendix model (AD-9) the uses desiccant I've stopped finding water in my air tanks and oil seems to have disappeared as well. Given that, I believe I'm less likely to have rusting in the tanks.
If I could find a filter that I felt could be relied upon not to leak I would install them in the entries to the 6-packs. The typical ones at HD and Lowes are designed to do well in static situations but we insist on traveling over bumps and exposing them to Drivetrain vibrations.
