1989 W124 A/C Repairs/Rebuild/Upgrade - PeachParts Mercedes-Benz Forum

#1 06-18-2009, 04:57 PM

I hope I don't come off condescending here, but I DON'T GET IT! Why would you want to do all this work and go to all this expense with PF condensors and all sorts of dollars spent so that you can save $40 or $50 on refrigerant?

This sounds like the accounting methods used by the US Treasury Department!

You have already tested and found a leak free system. Add an ounce or two of mineral oil, evacuate thoroughly and recharge with R12. This will cost you a fraction of what all this work you're proposing and give you the system that was designed into the car with the refrigerant for which it was designed.

BTW, the evaporators in these cars do indeed have a reputation for failure, but don't buy into the notion that it is GUARANTEED to fail. My car is 21 years old with 310,000 miles with the original evaporator and NO leaks. It will make a Polar Bear scream for mercy and I live in Texas.

Tassie · #2 06-19-2009, 03:23 AM

Hi Larry;

I think you're right but there are several issues at play. Please bear with me.

One, the AC system is not working again therefore I am planning my options. I cannot legally obtain R-12 in Canada so for the ease of legally maintaining the A/C system I have to consider converting to R-134 refrigerant.

Two, I may have a leaking condenser (but not yet confirmed) so if that is the case then I want to consider replacing with a PF condenser but only if it easily installed (ie were those W124's equipped with R134 refrigerant also equipped with PF condensers or larger condensers to offset the lower efficiency of R134?). I have no desire to re-engineer an aftermarket condenser with new attachment brackets, new AC fittings, and new routing for the AC hoses.

Three, I had the understanding that replacing the A/C hoses was required when converting to R134. I have since read and confirmed by others that older hoses that have used R12 may be "sealed" therefore hose replacement may not be necessary. But if it is a source of leakage then new hoses are relatively inexpensive EXCEPT for the one hose with the fuel cooler. As new hose is worth about $10/ft I wanted to know if I could simply replace the hose and the crimp fittings for this particular item.

Four, I was looking for a long term repair not simply patching the system year after year. Of course, patching the system may be the most economical approach but if long term repairs can be done economically then why not do it right in the first place? Please note that I have no intent of throwing a pile of money at this. If repairs are necessary then I want to consider the long term options, the cost and the benefits for long term efficiency and reliability, make my choice, and proceed.

Five, if it is possible and also economical then improving the efficiency of the system is also desirable (for instance, is converting from the single fan to the dual fan an easy job? Looks easy but I may be wrong). However, I don't have all the answers (hence the questions) so I couldn't determine if improvements are easily available and cost-effective.

I hope this clears up why I am asking the questions. So far, it appears that leaving the system "as is" is the most appropriate course of action especially for those that have legal sources of R-12. I may have to simply live with the reduced efficiency of R134.

I certainly appreciate the advice and feedback.

Cheers,
Paul

remotemark · #3 06-19-2009, 11:06 AM

Quote:

Originally Posted by LarryBible

You have already tested and found a leak free system. Add an ounce or two of mineral oil, evacuate thoroughly and recharge with R12. This will cost you a fraction of what all this work you're proposing and give you the system that was designed into the car with the refrigerant for which it was designed.

Unfortunately, my 300CE was converted to 134 long ago and I can't just put R12 into it.