1986 C20 r12->134a conversion now fries every OEM/ACDelco original style compressor installed

I finally had my 1986 C20 AC converted to 134a a few years ago. I've had nothing but trouble ever since.

Within 1,000 miles every OEM style replacement compressor fails.

First question: Has anyone else had this experience? If so, looking for advice.

Second question: I'd be fine switching to a Sanden 134a compressor but since Original Air Group closed down I can't find the replacement parts and brackets for my truck. Anyone know exactly what brackets and Sanden from Classic Air will work? I don't a whole system replacement. I've had everything else replaced already. I just want to change over to a modern Sanden compressor.

Who's been charging this system?

Triple post

Quadruple post. WTF happened here?

Double post.

Double post.

I have converted many vehicles to R134a from R12 over the years. Never had any issues. GM, Toyota, Nissan, Honda, Volvo, Jaguar, VW, Audi.....and more.

I have some questions.

1. When you replaced the compressor did you drain the oil from the new compressor? (They get shipped, typically, with a full load of oil.) You are supposed to drain the oil from the original compressor and measure how much came out. Then drain the new compressor and add only the amount you removed from the original. If not you will need to remove every component and drain the oil then add what the spec. is for the system or each component, depending on how the repair information lists it.

2. Are you reducing the charge weight by 10%?

3. Are you replacing the accumulator each time?

Too much oil reduces the system's capacity and can cause liquid refrigerant to enter the compressor. This will damage the compressor severely just like water going into an engine.

Is there debris floating around? If so, you need to either replace everything or flush the system and get the debris out of there.

You did not say what the failure is, compressor type and why it was converted in the first place.