I have the above unit and it is not coming up to pressure to shut off. Starts fine at 0 psi not abnormally noisy but when the pressure builds it's starts making a screeching noise(like 100 nails on the caulk board) Never gets any more then about 90-95 psi.

I first thought that it was the valves but took it apart this weekend and they seem normally when comparing them to the kit I got from you guys. So I dug deeper into it, the cylinder wall looks perfect.

I am wondering if it blowing past the rings?? They look to be made out of plastic not the type of material I expected to see in a component like this. Kinda lost at what to do next other then throw more parts at it.

Thanks in advance.

MTR,
This isn't a humming noise like its a compositor. My first step was to remove the belt and run the motor to isolate motor, really quite compared to when the pump is running compared to when it worked even. Everything is moving freely, belt is new, tight and aligned.

It's a building sound; as it builds pressure it intensifies, makes you want to rip your ears off so you don't hear it when it levels out at about 90-95 psi. But of course doesn't shut off cause it never reaches the limit switch max psi.

VH300000AV