And what does it do? My air compressor cannot get above 60 PSI, it should get to 120 psi. I noticed this piece is where I am losing pressure. Can I replace it?
Supposed to allow air through until certain pressure and then it closes. Basically the opposite of over pressure valve. It allows motor to start without having to build pressure for a few revolutions.
Pretty easy part to replace. Google should find you many.
Agreed, It looks fairly easy to disassemble and clean. I would attempt that before replacing. You may find a YouTube vid or two showing how. Pvc thread tape is your friend. Dirt in the valve will stop it from closings properly as pressure builds.