Rolair

Old Part Numbers: 031-0077, FC347043000, MF347043000Check Valve. Replace if unit leaks continuously around pressure switch or compressor struggles upon re-start. If your pressure switch is leaking...

Comes with paper element.

1/4" Male NPT with unloader

If you start to hear knocking from your pump, then you need to replace your bearing inserts. Check crank to make sure it is not damaged.