Air Compressor 101

[Burt Alcantara]

Never mind. Got if all sorted out.

[Mike Cutler]

According to Makita your air compressor has a cut in pressure of 100 psi, and a cutout pressure of 130psi. This means that your Tank Pressure, the gauge on the left, should always be somewhere between 100 and 130 psi, as long as the demand does not exceed the ability of the compressor to keep up.
The gauge on the right is your regulated air pressure out. It should vary from 0-130 psi, and be independent of tank pressure if working properly. Can you adjust the regulator knob on the right and see the pressure on the gauge change while the compressor is in service?

Your airbrush has a diaphragm operated pressure regulator that has no downstream pressure sensing. The output of the regulator is a function of the deflection of the diaphragm due to the differential pressure across it, and the position of the needle valve in the output port. The spring inside the regulator sets the pressure. Too much pressure and an excess port is opening up blowing off excess pressure.
In short, the pressure to your regulator is too high, or the regulator is broken. Unless it somehow is hooked up backwards.

Trying dialing the regulated output pressure, as read on the gauge on the right of the Mac 2400 to minimum,and then slowly bring it to 40 psi as indicated. then try your airbrush regulator. It should operate just fine with a 5 psi differential pressure across the diaphragm. 40 in/ 35 out.

Ya' fixed it!!
Ha, ha . I can't type for beans. I'm too slow.
So what did you figure out Burt.

By the way. That looks like a nice unit.