AC again-83 240D-What is best Compressor to use?

[Carrameow]

My Freon 12 system has been long dead. I'm about to rebuild the system to CFC 134. I understand that there are several models of Compressor around, & I think someone mentioned a Sankyo being the best. If not Sankyo, what is?
I'm very concerned--I commute two hours twenty minutes a day, I need the AC to keep me awake, plus it get so humid on the East Coast.

[stevebfl]

There is only one compresor for that year and it is the R4 GM compreesor. They are about as cheap as anything made, they work fine with r134a when installed new and using ester oil.

The Sanden compressor is a good alternative for diesels up to 1978 with York two cylinder compressors. These compressors are not suitable to retrofit. The R4 comp is very unusually shaped and mounted which would make it very hard to use anything esle.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

Carrameow,

I was the one who posted the mention of a Sanden compressor. I have two Euro 240D's, one a parts car with these compressors on aftermarket acir conditioners in the same location as your R4, low on the drivers side. The R4 is a terrible compressor.

As Steve said, when you replace the R4 use a NEW, repeat NEW, R4 compressor, not a rebuilt. If you do that, there is probably not a need to convert to a sanden or sanyo, or whatever it is, I will check to verify the brand. If you converted, you would have to have two hoses made to replace the manifold that connects to the R4 compressor.

I really went through a nightmare with an R4 on my wifes 300TD station wagon, and hate the R4, but a NEW one, not a rebuilt would probably work out okay.

Don't forget the ester oil, a new filter drier, and it wouldn't hurt to pump it down for 24 hours before charging it. The good news about changing to R134 is that if you have a leak you don't lose $100 or more worth of refirigerant.

Best of luck with it.

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Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
Over 800,000 miles in
Mercedes automobiles

[stevebfl]

Its too bad you had such trouble with an R4. I probably had its brother last week but I've been there before after flushing ten times we were still getting black flush solvent. Too bad cause that relatively nice 83 300SD is probably history after we gave her a price for evaporator and condenser replacement. We'll see when it gets really hot how she handles it.

After over twenty years of replacing 50 units or more a year, I can speak with experience that the R4 is as good as it gets. Problems come (from rebuilts always) from incomplete repairs. If you want a really junk compressor you can look at all the Nippondenso compressors used since 1986. They have teflon coated pistons and fail in a condition know widely from Fords licenced Nippondenso copy "Black Death".

They almost always fail like that rare R4 failure. Their problem is that the burned up mess of Aluminum. teflon, oil and refrigerant forms a temp dependent liquid that hardens in the condenser and when flushing it looks clear but upon reuse the mess turn liquid again when the condenser heats up. It gets worse on the 300e because the evaporator is a multiple entree unit and when flushing it is real easy to leave flush in the evaporator. As the gas pressure clears out the upper level and all the flush force then goes through the clear tubes and the lower tubes retain flush wasting the new compressor.

Nem R4 units (with clutches) can be purchased from your AC-Delco jobber for a bout the same price as a Sanden, whuch is as cheap as it gets. You can probably kill a good system with an Autobone rebuild for less than 70 bucks.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[be459]

Steve,

For those people having the Nippondenso compressor, should they start replacing it with other model now before problems start?

What model can be used to replace Nippondenso for r134a conversion?

Thank you.

David

[stevebfl]

Unfortunately with the advent of serpentine belts the changing of compressor brands has become near impossible. They are just too specifically mounted.

When the only answer was a POS rebuilt or a new MB for a grand we used to use Toyota and Acura 10P15C and 10P17C Nippondensos for about half the price. MB list on their rebuilts without clutch now is $443 for all of the early Nippondensos. The only improvement might come from using a 10PA17C later 300E compressor on the early cars. I have never tried it but you would have to change the clutch and manifold assy and mounting bracket I imagine and you might wind up with a necessary belt size that doesn't exist as there may be other pulleys that changed too.

We don't do early 300E retrofits if we can avoid it as the early 15C compressors are under powered to start with. I think the 210 chassis has a variable displacement compressor but I bet its capable of 20 or greater by whatever measurement that represents.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[Benzmac]

Steve, you are right. All of the newer cars have the variable compressors. They are great.
I am not going to retrofit any of the early 124's untill we are out of r-12. Some just don't cool well.

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Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Wish I would have had this forum about six years ago.

The R4 compressor nightmare I went through was indeed with a rebuilt compressor. I did flush the system THOROUGHLY, and still had massive problems. No more rebuilt compressors for me.

Thanks for sharing all the experience regarding this subject.



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Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
Over 800,000 miles in
Mercedes automobiles