The pressure switch may also incorporate an unloader valve that reduces tank pressure when the compressor is turned off. Many articulated-piston compressors are oil lubricated.

Mini Truckin' tests Viair, Thomas, and Oasis on-board electric air compressors, only on minitruckinweb.com, the official website of Mini Truckin' Magazine.

The vehicle's refrigerant will leak out and reduce the total pressure in the system, causing the low-pressure switch to disengage the compressor.