20 Most Recent Craftsman 25 gal Air Compressor 3 12 hp Vertical k 2 Stage Oil Free Pump - Page 9 Questions & Answers

No on the torch, it might warp the shaft. The use of an arbor press us highly advised

make sure it is on a 20 amp breaker

replace gasket

This is usually caused by long extension cord, leaking check valve or weak capacitor. Most likely leaking check valve. Easy to check, run compressor for a couple of minutes and shut off. Listen for air leaking from pressure switch or at the intake filter. If leaking, let out air and remove check valve and look for debris stuck under the valve seat. To find the checkvalve, follow the air discharge tube from the head of the compressor to the tank. You should find a brass or chrome valve threaded into the tank. If check valve is not leaking, suspect weak capacitor or long cord (motor shop will test cap for free). Good luck

Cbillgreene: Your compressor is leaking air somewhere between the compressor head and the tank. With the compressor running, feel carefully around the ends of the tube that leads from the compressor head to the air tank. You will probably feel some air leaking around one end or the other. If so... remove the tube and find out which packing has failed.

Sounds like one of the following three possibilities:

Too small of service to the unit... You need 20 amp and #12 wiring.

Too long extension cord with too much voltage drop.

The "unloader" is defective. This is a little valve that MAY be a part of the pressure switch that bleeds cylinder head pressure at shutdown to make starting easier. At shutdown you can usually hear it "exhale".