Last week I developed a massive air leak when I raised my tag that I traced to my right rear tag axle lift chamber. That is a Type 36 single chamber brake chamber. Preovost wants $367.00 for a new one. This is a perfect example of a job that is easy to do and will save you a lot of money. The rubber diaphragm was $7.00 from my local NAPA store. Total time to remove, fix and reinstall was 3 hours, and I went real slow to take pictures and get it right.
1. Start by raising the rear of the bus up on the air bags as far as possible.
2. Use blocking/ jack stands under the rear body support points.
3. The can can be accessed by going above the tag axle tire.
4. Remove the air line, there is no pressure on it unless the tag is raised.
5. Remove the pin that holds the clevis to the tag axle lift arm.
6. Remove the 2 nuts that hold the can to the bus frame.
7. Disassemble the can by removing 2 nuts and bolts that hold the clamp tight. The spring is a very light spring.
8. Install the new diaphragm
9. I used a work bench and a strap to hold it together while I put the clamp back on, I was working alone and needed 2 sets of hands. With a helper the strap would not be needed.
10. Re-install is the reverse of installation.
Leak now fixed.