[madmatt2024]

Buzzing inside the car is more likely to be a blower motor than an A/C compressor issue. 90 PSI on the low side typically means that the compressor isn't running and with it working for 40 minutes before stopping, I would lean towards an electrical or A/C clutch issue.

 

[madmatt2024]

Now that is really strange. What is your high side pressure? If it is a compressure failure then you will have to do far more than just replace the compressor. All of the lines will have to be flushed, the condenser and evaporator will have to be either flushed or replaced, expansion valve and dryer will have to be replaced, and new refrigerant oil added before the system can even be refilled.