AC conversion

Hello Benzmac, My 89 190e 2.6 has a small leak. Filled it up last year Memoriable day and now it's just on the cool side. I'm wondering how best to fix it. Convert to 134a and run stop leak... run stop leak for r12 and refill... maybe I can find the leak and fix it... When I check around the AC shops everybody warns me about the condensor and many many hundreds of dollars to fix/replace.

Bill

[ctaylor738]

From experience with my 300E -

Do a search on "AC" or "R134" and you will find advice from Benzmac and many others.

If I were you, I would fill it with R12.

I had a seized compressor. My decision was to replace the compressor, drier and its switches, and expansion valve and go to 134. Total cost of parts was about $600 from the PartsShop.

My mechanic says you must change the compressor because the oil is contaminated and you must change the drier and get the R134 switches. The exp valve is "calibrated" for R134. The majority felt that the condensor replacemant was overkill.

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Chuck Taylor
Falls Church VA
'86 300E 5 speed
'95 C220 (wife's car)
'98 Porsche Boxster
Past: '79 280E, '82 300D (18 yrs), '77 240D,
4 250C's

[Benzmac]

The good thing about a 190 is that the evaporator is easy to replace. I would have the expansion valve checked closely. If it is oily and dirty, I'd do it and go back with R-12. The converted cars with old compressors do not ever cool as well as the r-12's/

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

When I converted my 81 300D I replaced everything. Worked well. When I converted my 82 300SD I evacuated the system and checked for leaks. There were none. So I charge system per the instruction, 2 cans of R134 then a charge of oil, and another can of R134 held top up till system would not take any more. This AC unit works better than any system I have ever had in any car. I was surprised. R12 is better but my luck with R134 has been positive. Just my .02.

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Mark B

82 300SD 225k
81 300D dead at 207k