Posted 1/12/2026 07:22 (#11506588 - in reply to #11506550) Subject: RE: Primary and secondary air guage on peterbilt379
Mount Vernon, WA
Normal allowable difference between cut out and cut in pressures are about 25 PSI. If it doesn't go below 90 I wouldn't be too concerned. Your shop air compressor acts in a very similar manner I'm sure.