20 Most Recent Campbell Hausfeld Husky Gravity Feed HVLP Spray Gun, HDS79000AV - Page 8 Questions & Answers

I guess you mean it leaks air from underneath the On/Off switch?If that's correct, it sounds like the check valve is leaking. On the tank there should be a pipe that goes under that switch. At the tank end of that pipe, there is a check valve. Before you unscrew it MAKE SURE THERE IS NO PRESSURE IN THE TANK!!! You should be able to unscrew it, the check valve consists of a light spring and a plastic or rubber stopper looking thing, have a look at it, if possible clean it or replace it. Put it back together again, and try it now

Water is condensed from the compressed air it makes and this can settlel in the switch diaphragm, in cold weather is can freeze and prevent the switch from working.....

Some air compressors have 1 or 2 pistons one the piston sleeves could have a crack or a small hole what i would do is clean every thing and make sure the inlet valve is open and the unloader valve is clear of debris but if it doesn't help then you propably have a cracked piston sleeve I hope i was helpful ( tell me the model of it and i could get you more information)

A 30 Weight Non Detergent Oil will work for your compressor. Make sure to fill it to the fill line on your dipstick. It will have an indicator on the bottom of it telling you where the maximum amount should be. Be sure not to pass the fill line or the oil will be sucked into the pump.

If you already replaced the pressure switch, then the issue is with the motor. It sounds like the problem may be with either the capacitor, or with the motor fields. I'd suggest taking it to a service center and having them look for any metal debris within the motor fields, or checking the capacitor voltages.