Craftsman air compressor, oil build up in the air line

Piston Rings or Seals have failed.

Why does oil come out of the oil fill tube? ' About Air ...

https://www.about-air-compressors.com > why-does-oil...

It won't build up any more than 40 psi. ... I have oil blowing out of the oil breather on the pump. ... worn, and you are getting oil blowby into the air pressure chamber as the compressor runs. ... Doug in s.d.ca on Identifying An Older Air Compressor; Doug in s.d.ca on Craftsman upright air compressor slow starting and blowing ..

Oil free pumps do tend to blow the piston ring (not too expensive) available at searsparts.com. Remove covers to pump and manually turn crank until piston is at top and look at the condition of the cylinder neer top, If it looks scratched, order cylinder kit with piston ring. If it looks good and shiney, could be the valve plate in the head. There are reed valves that tend to break. Run pump however with covers removed and check with soapy water for air leaks and repair as needed (air leaks under the cover will prevent unit from filling). Good luck

Sounds like the compressor has failed -- probably the valve -- tear down and rebuild is probably the solution, or replace compressor, or just buy another unit. My nature would be to tear it down and see what's going on.

its either a reed valve broke or corroded beyond function.remove the head and look at the plates.look at the piston rings while your in there sounds like its just worn out,but i just rebuilt mine for 80 bucks thats all the gaskets plates and piston with sleeve.the repair takes about an hour.if you do tackle this yourself remember the fan for the air cooling may be reverse thread.try not to break it.noone mentioned this to me but i got lucky and tried the other way before i got serious about removing it.good luck

I would have to say if you are blowing oil out the crankcase that you have a piston or rings problem

thats your piston rings gone buddy thats all it can be

Not the motor, but probably the compressor shot. Heat from friction (due to running without oil) probably scored the cylinder walls, which allows air to escape past the piston and rings, making the compressor VERY inefficient. Some compressors have replaceable cylinders... Not sure if the very small ones do or not.

It sounds like you may have a broken reed on the diaphragm plate. This is located at the block. Remove the cover, and look for a cast metal assembly with fins. It will be attached to the side.

The pressure switch has snap action contacts that are opened by a diaphragm pushing against a spring mechanism. Unplug the compressor and remove the cover to the switch and look for the contacts. Make sure that they are not welded together from use. Move the on/off lever to see if they open and close. You may have welded contacts or broken mechanism within switch. A factory replacement is expensive, however if you are a tinker-er you can use a lower price generic pressure switch available on ebay. Switches are sold by pressure range, you need a 120#. Fittings may need tweaking. Enjoy

YES IT MAY BE THE CAPACITOR . IT COULD ALSO BE THE WIREING IN THE MTR, THE PUNP ITSELF.