I have looked through the many of the A/C threads and post but haven't quite found the answer to this one - my appologies if it has

I have a 1983 300SD with a bad R4 compressor . I check it with UV dye and it seems to be leaking in the back where the back plate piece joins the housing . The system works when there is enough refrigerant in the system
Is this a big o-ring seal which is easily replaceable . A friend has told me that the R4 is not s very good compressor . I don't mind replacing the compressor with another R4 if I can find quality rebuilt for around $ 100 . What GM vehicle applications fit - I saw something about 9 o'clock for my caqr but saw them with other coil clock positions ( 2, 12 ) for other applications) . However, a friend has told me that the R4 compressors are not good and it would be better to go back with something else if posssible. What other will fit most easily ( what mods are required ).

Also, where is the expansion valve for this 1983 300SD system located ? Is it in the same location and R&R the same as DieselGiant's description for the 300D ?

Thanks

don't repeat don't buy a rebuilt r4 go buy a new one.nothing else will fit without a lot of mods.caution. new r4's come with no oil in them.you must oil it up on bench by turning clutch and adding oil [a 3 handed job so get help].the expansion valve in sd[126 body]is under instrument panel above accelerator pedal.you will need large 27mm wrench and crows foot wrench will help.good luck. david poole european performance dallas tx.

I have looked around on the web for one a new R4. An R4 with the 9 o'clock coil position for this car is mentioned . Can you use another clock postion model Delphi - GM - Harrison R4 and extend the coil connection wires to fit or is there something more to this ? - Thanks

Some models use SAE mounting bolts instead of metric. Some have pulleys that are not MB compatible.

Assuming that I found one that is metric and has the same pulley , what if I used one that has a coil terminal in a different clock position and just extended the wire from the body making sure that there was no mechanical interference ?

I installed a rebuilt R-4 from Advance Auto, they had it in stock, one year warantee. It uses the metric hardware, and the clutch connection is at 4 o'clock like the original. Just my 2 cents, YMMV, Chuck.

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2000 C230 Kompressor "Frosty"

2007 PT Cruiser
2001 VW TDI Beetle
1999 Landrover Discovery II
1971 Corvette

Gone: 97 Cabrio, 83 240D, 93 VW Eurovan, 95 Volvo 850, 93 Chevy Astro Van, 77 VW Bus, 99 VW Jetta, 74 VW Bus