Switching to 134a in 82 Corvette

[blackimpala]

82 Corvette. Last winter (2015) I removed or flushed all parts in the system. Replaced compressor "R-4", drier, orifice tube added 150 pag oil some to the drier and some in the compressor aprox 8oz. charged with 134A ran fine for most of the summer then compressor started screaming. I put another new compressor on and checked the orifice tube found it to be clogged with black gunk, cleaned the tube and reinstalled. This time the compressor didn't last long enough to charge with 134a. orifice tube a little dirty but not clogged. Doing the whole thing over again. Please tell me what I may have done wrong or what I can do to prevent it happening again.

Thanks
Floyd Wilson

[Tim]

A proper flush is in order. I've never been a fan of converting corvette's.

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