Is your compressor check valve leaking or seized? This SMC check valve kit is a direct replacement for the standard 1/4" Viair check valves that are located on the end of your compressor leader line. The SMC check valves are more rugged and are a must for those who daily drive in below freezing temperatures.
Testing your current compressor check valve for a leak is easy. Starting with a cool, unpowered compressor, remove the filter housing and put your finger over the intake port for 30 seconds to a minute. If you hear or feel air escape when removing your finger from the compressor intake.. you're going to need a new one.