dvs_dave

I’ve finally got around to doing this after having the parts sat on the shelf for years. The OEM WABCO compressor finally got weak enough that it took minutes, or just failed to fully adjust height without tripping out on high temp. I was also getting regular implausible pressure reading DTC’s, and it was failing the accumulator output test. Never saw a reading above around 8.5 Bar. Minimum permissible pressure is 7 Bar (from accumulator output test). It was also starting to get noticeably louder.

Anyway, pretty simple job in the grand scheme. By far the hardest part was getting the compressor out. Access to the outboard mounting bolt is very difficult, especially with big mitts like mine.

Here’s a couple of pics of the original piston ring and the replacement. You can clearly see the difference in thickness. The compressor crankcase was also full of brown dust which was presumably material from the original piston ring.

Post rebuild, the compressor is noticeably quieter, and the suspension now changes height in seconds rather than minutes. Accumulator output test passes, and the accumulator fill (in basic settings) gets to 16 Bar, per spec, no trouble.

Overall a good job done, and is not very expensive at all.

Here’s a link to the rebuild kit:
https://www.bagpipingandy.com


Original worn piston ring


Replacement piston ring