This step-by-step repair guide gives instructions for replacing the check valve on an air compressor. The check valve stops compressed air from flowing back into the pump from the tank. If the check valve is stuck open, high air pressure from the tank flows back into the pump head. The high pressure in the pump head won’t allow the piston to move, and the motor can’t start. Replace the check valve with the manufacturer-approved replacement part.
Use these steps to replace the check valve on common Craftsman, Dewalt and Devilbiss air compressors.