I suspect he's guessing. I don't know which system your vehicle uses but regardless, there's a pressure relief valve in the receiver-drier that would have blown off if too much pressure built up.
Starting somewhere in the mid '90s on some models, Chrysler started using compressors with a variable "wobble plate". It self adjusts according to the low side pressure. When there's more heat load, the pressure goes up due to a rise in the refrigerant's temperature as it leaves the evaporator in the dash. That higher pressure adjusts the wobble plate to make the pistons take longer strokes and pump more refrigerant. That way the compressor doesn't have to regulate by turning on and off. That can be felt and can be annoying.
The other system uses an expansion valve, often called the "H valve". It is a controlled leak that is adjusted by a gas in a sensing bulb on the evaporator that expands when it warms up, and that expanded gas pushes on the expansion valve to open up and let more refrigerant in. Those H valves caused a lot of trouble but they usually got handled when the vehicle was still in warranty. Depending on how they stuck, the valve would not let enough refrigerant through to cool the air or it would let too much through. Then the evaporator would drop below 32 degrees and the condensed humidity would freeze into a block of ice that blocked air flow.
I don't like to argue with a mechanic over something I can't see or diagnose myself, but I'm not sure I follow his reasoning. I find it hard to believe something else in the system is going to damage the compressor. If it is just the clutch that has failed, that is not uncommon. They seemed to have a lot of clutch coil trouble starting around the late '90s to 2000. It's a Japanese part so you'd expect to find better quality, but failure is common.
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Friday, July 6th, 2012 AT 11:16 PM