Compressor not building pressure and continues to run

https://www.google.com/search?q=Northstar+Gas+air+compressor+M459392C+continues+to+build+pressure+even+after+idle+down

1. Pressure switch: The pressure switch may not be shutting off the compressor when it reaches the set pressure level. If this is the case, the switch will need to be replaced.
2. Check valve: The check valve prevents the compressed air from flowing back into the compressor pump when it is not running. A malfunctioning check valve can cause pressure to continue to build up, even when the compressor is idle. A damaged or worn-out check valve may need to be replaced.
3. Piston rings: If the compressor's piston rings are worn or damaged, air can leak past the piston and cause pressure to continue to build even when the compressor is idle. In this case, the piston rings will need to be replaced.

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This is an easy fix.. you need an new safety valve or a new switch.

If the safety valve releases pressure before the max pressure replace it.
the switch has a cut in pressure of 120 psi (this means compressor will start when pressure falls to 120 psi.
The cut off pressure is 150 psi. This means the unit will shut off at 150 psi.
You need to watch supply pressure to see if it exceeds 150 psi. If it does replace switch.


Safety Valve Part Number:AB-9415379
Pressure Switch Part Number:AB-9415626

This could possibly be, you have some water from condensation buildup inside the tank, liquid does not compress. Before this next step make sure the tank is to 0 psi! Now, there should be a relief valve Wingnut on the bottom. Loosen the wing nut and drain as needed. Then retighten the wingnut (Do not overtighten). Plug the compressor in and try it. My second suggestion is, the psi adjustment pressure knob could be faulty replace as needed!

you must have wired the new pressure switch incorrectly .when the pressure switch opens it will release the head pressure so your compressor must be running with the pressure switch contacts open should be 4 connections 2 marked motor which is from your compressor and 2 marked line which is your power coming in

is the compressor cutting off or does it just continue to keep running and never gets above 40 psi?

The problem with compressors not building pressure is usually a bad pressure switch or bad regulator. Does the motor shut off at 20psi or does it continue running and not build pressure? If the motor continues to run with no increase in pressure, the you should go over the machine looking for air leaks from your regulator back all the way to the motor. Any air leak while the compressor is running can cause the pressure to "peak" way before the intended shutoff that it is regulated to.

the regulator is failing to do its job. make sure you have it set properly. if you did, you will likely need a new one. also remember to drain the compressor every month to prevent rust from moisture build up in the tank. good luck.

Check to see if air is leaking past 'pressure relief' valve. It's probably leaking and that's where all the air is going.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

sounds like the regulator is fualty.

compresors pump, valvs or sels gon!