I have an old craftsman compressor 4 cyl.?

Question

The motor capacitor was missing,so I took one off a washing machine motor, It run fine without a load,but when I hook up to compressor it throws the breaker. maybe the compressor is to tight,or the backflow valve,seems to be working, Discontiued parts. thanks for answers..

Answer 1

If you are saying that the compressor trips the breaker after it has ran once already, then you have a bad/misadjusted unloader valve. This is on the pressure switch, it should have what is usually a 1/4" tube that runs from it to the line going from the tank to the pump. This valve bleeds off pressure when the compressor stops so that it can restart without a load. Normal operation is to have a momentary hiss from the pressure switch when the compressor shuts off.