I am getting an occasional "air suspension fault" indication and a low back of the car after sitting overnight. It indicates a leak in the back but while doing some repair with the front bumper off I noticed something unusual (maybe, that is the question).
While the compressor was operating it was venting pressurized air out of the bottom of the assembly. There are two v-shaped holes on both sides where the air escapes. It does not leak out when the compressor is not operating.
Is this normal?

 

The valve block vents through the compressor, so any leaks from it will sound to be coming from the compressor. Need to check to see if the block valves are leaking.

 

Thanks for the reply. Why is it venting out of the bottom of the compressor only while (whilst) the compressor is operating? If it was leaking, would it not leak continuously?
I am thinking there is a failed gasket in the compressor but I also know the system vents on the compressor somewhere. The compressor is only about two years old (Wabco I think).

 

Solved.

It was the compressor assembly. It was under warranty so I just got a replacement and installed it yesterday. Works like it is supposed to.
My guess is that something in the vent/pressure relief failed and started leaking. That was causing the air venting out of the housing and also the deflating of the air bags themselves.