Leatherman,

Yes, that's true to maintain warrentee on an MB compressor. I've flushed more than a few and not had failures. My last one was at 125,000 miles and still going. That's good for Texas=)

Some ppl add a filter on the return line before the compresor too. Big thing is just flushing really well. Obviously, he can buy a compressor, manifold hose, dryer, and expansion valve from mercedes. Assy and if the compressor dies within 2 years- mercedes will pickup the tab.

Oh- make sure to clean (I replace), the sharder valves. Little bits of metal will hang in those openings.

I'm not aware of "internal passages in the R-4 manifold pipe", but are you mixing with the Nipendenso compressor manifolds??

Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E