DeVilbiss air compressor will not build pressure

SOURCE: Makita MAC2200 runs fine (with new Manifold Switch

I have worked on many makita compressors and have run-across this problem on a few of them. Your compressor has a check valve that is supposed to hold tank pressure after the switch reaches set pressure. There is an unloader valve built into the pressure switch that releases the pressure in the discharge hose after the unit shuts off. The unloader allows the compressor to restart with-out any pressure in the discharge line. If the brass check valve is leaking pressure back into the system, air will leak out of the unloader valve. Follow the discharge line to the tank and you will see the brass check valve. To test valve for fault, run the compressor till it builds around 80 psi and unplug the unit from the wall outlet. Remove the 1/4" hose connector from the check valve and check for air leaking out of the valve. If it is leaking you can order form www.toolpartsdirect.com. or call the makita 1-800 number. The price is about the same. Good Luck on your repair.

SOURCE: kobalt air compressor will not go above 80PSI

if this is an older or much used unit, cylinder/piston may be worn, unable to push higher psi, which would explain no leaks. if newer unit, seems like regulator unit/valve faulty

SOURCE: Craftsman 30 Gal. 150 PSI Not building air over 45lbs

The compressor valve may have a faulty gasket or seal, and maybe leaking air internally. Or the compressor might be going downhill. You can try to replace the valve seal and see if that makes a difference, otherwise you need to replace the compressor.

SOURCE: Was working normal suddenly will not build pressure

Maurader1 an apprentice has this problem solved and is spot on. All these gurus and wiz need to stick to the basic and common sense. The first place your pump will give out after use or abuse is the gasket. All this garbage about defective reeds and defective pressure switch is a lot of nonesense if you first don't rule out the most common problem the head gasket. I'm cheap and this thing has paid for itself 10 time over. You can get a gasket kit for $7, but I fabricated a gasket out of the back of my notebook and sprayed some gasket spray and been working like a charm ever since.

SOURCE: pressure in the tank only builds to 30 psi

Bad check valve. But I would check the regulator, by turning it down to about 10 PSI and running it and see if it builds again, if that works then it is the check valve. But from what you are saying I would replace the check valve anyways.