95' Jeep G Ch. - Air conditioning only works a bit after startup.

[juno]

Last year I replaced the compressor and clutch with a one from a junk yard. Everything worked fine all summer and full. The A/C was practically not used all winter.

About four weeks ago I started to use the A/C again. Initially it was working fine, but then it started to malfunction. It would only work on a cool engine at startup for about the first five minutes then the clutch would not engage.

I have put a whole can of R-134a into the system and the pressure reads 55psi when the clutch is engaged, however after about the first five minutes the clutch disengages and the pressure goes to 150psi.

I am not sure what is causing the A/C to stop running after the startup. I was hopping that I could get some advice before I start taking things apart.

As always, thank you in advance,

-Jay (Jeep Grand Cherokee 95’)