2nd air gauge not working

[Wiseman]

(04-12-2016 )allan82782 Wrote:  I have an 08 prostar with a cummins isx and I been having issues with my air dryer the problems are my primary and secondary air gauges rises to 150 psi then the emergency blow off valve sets off. I replaced the governor and still no luck so recently I replace the entire air dry and it seem to work for a week or so then ride back to the same issue again I'm starting to think it is my air compressor but before I spend that kind of money I want another opinions.

Replacing air dryer and governor is a good ting you did . The problem in your case is most likely in the compressor head . More precisely the unloader piston moving the plate back and forth. There's O-ring on it . What's happening is compressor gets air from intake manifold . Unfortunately there's not only clean fresh air but also recirculating EXHAUST gases containing a lot of black stuff that kills engines and compressors ....and our pockets . I hope you got the picture. It's up to you to replace the whole compressor or only head or repair the poor thing yourself.