compressor repair

If you have the model number in the sears format (Example:106.48062890) you can find exploded views and parts lists at

If the motor shuts off before getting to max pressure, then suspect a bad regulator switch.

If it justs keeps running without shutting off at the regulator switch setting, then suspect worn rings or leaking internal valves ( most commonly these are reed valves) if its a piston model - leaking diaphram or valves if diaphram model. It could also be the safety/pop-off valve leaking.

Check and change oil regularly, and drain condesate regularly to prevent tank rusting.

my 25 gal compressor doesn't want to go above 85 psi. Maybe a faulty regulator or ? Does anyone know where I can get a repair manual on compressors. Mine is Craftsman. Thanks, Paul

There is an adjustment inside the switch box. You will likely find two screws. If I recall one sets the off and the other the on pressure. Good luck. tonyg

How are you judging 85 lbs? Do you have another gauge or can you put a tire gauge on a fitting to check it? Try to perform this check ahead of the regulator. This would tell you what the compressor is producing.

The regulator has little to do with the pressure that a compressor can produce. All it does is allow delivery of the already compressed air at a "regulated" pressure.

It would help all of us to know whether this is a new-to-you compressor or one you've had for some time. Is this a new development? There is box close to or actually where the cord goes to the compressor. This box senses the maximum pressure and shuts off the compressor and establishes the come-back-on pressure. This thing is called a pressure switch, here is a picture:

Thanks all for the help. My compressor is about 10 years old. Until recently it would go to approx. 120 psi. I have two gauges. Looks like one is the tank pressure and the other the delivered pressure. The motor will shutoff when it (the tank pressure) reaches 85psi, so I think it is capable of higher pressures. I'll take a look at the pressure switch to see if it is adjustable. Thanks again, Paul