Pull the belt off & check the pulley bearing. Try to rock the pulley. If it rocks, or feels rough, the bearing is on it's way out.

When the clutch engages it can pull a bad bearing in to a different location where it makes more noise.

The condenser is the primary filter on the system. When a compressor fails & sheds pieces, they go straight to the condenser. Parallel flow condensers have tiny passages - in parallel. When the trash blocks one passage, you lose cooling capacity. They are hard to block completely, and are nearly...

Set the clutch gap as tight as you can without drag. .015 is good, it only wears bigger. .030 gap is too wide. Locate the vacuum reservoir under the hood. It should have a line from the manifold, and one to the firewall. Trace the firewall line from the cab side of the firewall. If nothing is workin...

The best tool is a high & low side pressure reading when the compressor is running. It may be running high pressures, cycling on the high pressure switch. Get the system pressure readings & post them here. Check the 3 wire pressure transducer in the high side line, and the 2 wire high pressu...

That compressor is mounted low on the engine. Any chance it is not refrigeration oil?

Generally an oil leak loses refrigerant as well. You say it still cools well. Did you happen to put dye in the oil charge when you put it back together?

.

A $150 rebuilt R4, HC refrigerant and no high side pressures.

Could be almost anything wrong here. Too much oil, junk compressor, undercharged, overcharged...

Call the compressor vendor at 810-679-9846 and ask them about HC's and no high side pressures...

The sensor is on the high side line someplace. AC Delco part number 1551343

Again, a Mitchell subscription can be a big help. You can screen shot the wiring diagrams & save them, that alone is worth the $20 charge

https://eautorepair.net/Marketing/Default.asp

No friction material. Metal on metal.

Be sure to set the gap correctly when you reassemble it.

The high side is a 3 wire pressure transducer that feeds high side pressure information to the PCM. The PCM makes the fan speed decision. It is not a simple switch, and is not adjustable. It is a 5 volt input, with a 1 to 4.5v output. The sensor could be bad, or the wiring to the sensor. The high si...

Many times someone has a vehicle for a few months, and has no history on it. Since you have owned it for a long time, you know that this is a new issue. You replaced the entire system - was there a reason to go after the Evaporator? Your radiator fans would be the logical place to start. I believe t...