My 190E was converted to R134 last March, and it worked all summer in Tucson. Now, it is not working. Earlier post (last week) has all the tests I have done. Still have not gotten it in to check if the R134 is still there.

But I still have this question: is R134 conversion really a problem?

I am not an A/C expert, but have read many posts here about the R12 vs. R134a in older MBs issue.

You'll find techs who say stick with R12 and you'll find techs who will tell you they've successfully converted many R12 cars.

I sometimes wonder if a lot of the R134a failures are the result of incomplete migration? Wrong oil used, system not flushed, receiver-dryer not changed out. The list goes on.

Is the clutch engaging the compressor? If so, what are your vent temps?

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Being a high volume shop in Florida we started converting cars the same year 134a came out. We have probably converted a thousand cars or more of many different makes. We have had scores of customers tell us their ac was never that cold before, but in reality most of those were cars that had been deficient for long periods. After more than a decade, experience has proved that a conversion will work less efficently than a proper working original system. A conversion will likely leak in the first three years and probably it will leak from the compressor even if it was new with the conversion.

R12 is still available and only two thirds the price it got to at one time. R134 while receeding this year got to more than half price of R12 wholesale. The refrigerant is the near the cheapest component in the system. I no longer see any reason to convert and numerous reasons not to. WE did one on a 126 body last week because the customer was dead set about "upgrading" his car. A victim of propaganda it seems. One doesn't argue with customers. So we did it and it worked great. With a new compressor it should last a few years. With a new compressor and R12 it should last indefinitely.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks. The clutch is not engaging. It still did not engage when I jumpered across the pressure switch before turning on the A/C.

The second posting is pretty depressing, but I appreciate the frankness.

Almost completeexcept for a/c issue. I tried put a/c coolant with compress conditioning. It came on after about 3sec into the refill for a 1sec and nothing else happen. Help

I took the car back to Mark at Benztek in Tucson. All the R134 had leaked out and some oil was leaking out too. Mark found some seals (I think, sorry, I'm no expert) near the compressor, like above it maybe, that were leaking. He replaced those and refilled the R134. He didn't charge me since he is not sure that there is not a leak at the compressor (which was not changed during the R12 -> R134 conversion). I'll drive it for a few days and have a look under the compressor, it should be obvious if oil is leaking as it's all cleaned up now.

a/c systems are very befuddling.

while i don't doubt the experts, i hope the conversion in my sons car lasts a bit ...the previous owner spent 3.5k re-doing everything from hoses to evaporator to compressor to drier. The receipts are daunting.

by the way....it is not as cold as the r-12 i have in my CE, but it is generally adequate.

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


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