Shut off before it reaches 150 psi turned up the regulator up but it stops about 60 psi should go to 150 psi

replace the regulator. the regulator tells the compressor motor when to start and stop.

nothing
it is the regulator that is faulty

If the motor doesn't shut off at the desired pressure then your pressure switch is either set too high or is broken/stuck. The pressure leak at 150 psi is the safety valve doing its job opening when the pressure gets to an unsafe level in the tank.

A regulator controls the pressure in the air line leaving the compressor and does not affect when the compressor turns on or off.

The pressure switch monitors the pressure in the tank and turns the compressor motor on and off when the switch closes or opens in response to changes in the tank pressure. If the compressor does not shut off, it is possible the pressure switch has been set to a pressure level that is higher than the compressor is capable of attaining, thus it does not shut off.

The compressor is capable of developing 150 psi and is noted as having a "120 psi cut-in pressure". When you say it doesn't shut off, does that mean it will generate 150 psi or more of pressure and fails to shut off or it develops less than 150 psi and does not shut off.

If the compressor does not generate 150 psi, then it is probably somewhat worn out and not capable of developing enough pressure to meet the factory high pressure limit. I would try adjusting the pressure switch upper pressure limit down to 130 psi or less (less if the compressor will not develop 130 psi) and see if this solves your problem If it doesn't,

If the compressor will develop 150 psi or more, then try adjusting the high pressure limit to less than 150 psi. If you can't adjust the high pressure limit then the pressure switch is defective and needs to be replaced.

The pressure regulator on an air compressor is designed to let the pump motor run until the pressure in the tanks reaches their safe level. While you are using the air the pressure drops in the tanks until it reaches the level where the pressure switch turns the motor on again and refills the tanks to their rated level. The pressure where these two things happen is usually with in ten psi above or below the rated levels because few regulators are so precise and are affected by temperature that they turn and off exactly at the rated pressures. If a pressure regulator is damaged or broken it is possible for the tank to either reach unsafe high levels or not turn on when the pressure drops to where it should restart the motor. If you are in doubt, have the regulator checked or replaced as overpressured tanks are very dangerous.

You hit the nail on the head ... it is the regulator. What does it say on the side? What are they advertising the pressure and the SCFM? (Standard Cubic Feet (per) Minute)

The boss recently bought a Husky. It is rated at 6 SCFM @ 200 PSI (as I recall) ... Its regulator turns the machine off at 240 PSI then delivers the air through a regulator. In my case, I throttle it back to 150 PSI so I can get 80 PSI at the end of my 75 foot long hose. The machine comes on around 150 PSI (or of course any lower number) and takes for ever to build pressure back.

Should you change the regulator setting? Only if you want to diminish the performance of the compressor and possibly void the warranty. If yours doesn't have a regulator, I suggest you add one.

I hope you have found my comments helpful ...

Thanks for visiting today.

150 lbs is the amount of pressure in the tank. When you connect a nail gun for instance you cannot nail everything at 150 lbs of pressure, it will blast through. The regulated pressure is at zero because you have the ability to regulate it by turn the know under or beside it to increase the output pressure to your desired amount. I was building a shelf last week and set my regulated to 80lbs with a brad and it blew through the panel and stuck in the floor. After you get to know your nail gun you will be able to regulate it between 60 and 80 depending on the type of wood. Panel - 50 lbs, Oak, 90 lbs, etc. Pleas remember to rate this solution high if it was helpful and explained it to your satisfaction.

adjust your pressure switch on your compressor .remove the cap and turn the screw clockwise to increase and counterclockwise decrease.turn the screw counterclockwise a bit and release some air till the compressor start pumping.then just before to reach 120 psi turn counterclockwise to stop the compressor at 120.then release some air again till it cuts in again and look at what pressure it will stop.keep going that way till you get your 120 psi.cut in should be around 90 psi(30 psi differential)depending what kind of pump you have (if the pump can handle 150 psi )you can adjust it to cut in at 120 and cut off at 150 and install a pressure regulator adjusted to 115 to 120 and get a nice steady pressure going to your nail gun.(the best way to do it!!!)

Sounds like a pressure switch to me. I would like to ask you a few more questions, let me ask you this, is the tank set at 60 Psi or the regulator? You can email me at phoenix.repair@hotmail.com for faster response time.

You prolly have a leaky gasket in the main valve. Air is leaking and causeing it not to go about 60psi, you probably have it set to reach a high PSI but since the leak is not allowing it reach above 60 it keeps cycling trying to get above it