We have two Thomas C-2 buses with the MBE900 engine and air brakes. The problem we are seeing is the air fitting in the back of the air compressor with a push lock connector starts to leak after a couple weeks and causes the air compressor to cycle every few seconds at highway speed. We put another new OEM fitting in and it only lasts a week or two before it starts to leak at the fitting not the tubing. Anybody out there seen this problem? Or better yet do you know of a better grade of fitting?