R134a is colorless and odorless, I had yellow dye added to my system while looking for leaks. There should be very little to no air in the system, which is why AC shops pull a vacuum before adding new gas. The dryer/accumulator is there to collect any water vapor in the system. The dryer must be replaced if a line is disconnected for any length of time, or humid air allowed in.

The compressor stops pulling the clutch because the electromagnet requires more volts at higher temperatures. Plus, with metal expanding with heat, the gap is going to be larger. Shims are needed to bring the gap back to its original gap, due to wear and tear over the years with multiple engagements.

Go ahead and shim the 3 points on the clutch. With a feeler gauge you can check the gap between the clutch and the pulley.

Because 40 psi is when the compressor clutch engages, you really want more than that. The compressor sucks r134a out of the line and towards the condenser, that lowers the pressure. When the pressure reaches 17psi, the clutch is released because the compressor will overheat with the reduced amount of r134a.

There are times when the compressor will overheat and shut itself down, but you need to be in stop and go traffic and temps above 95F.

Klaus


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Always willing to listen, just not able to take direction.