AC 'refresh' on SD - Options? - Page 2 - PeachParts Mercedes-Benz Forum

ROLLGUY · #16 05-30-2014, 08:42 PM

Of corse I would recommend a Sanden upgrade, but I am biased. I have had excellent results with 134a and a Sanden and all else stock. The key is air flow through the condenser. This is possible with this simple addition:
MOD- Condenser Fan & Compressor working together by adding a relay

I have recorded below 40 deg vent temps a couple times, with the average being at 40 deg most of the time....Rich

Graplr · #17 05-31-2014, 03:43 PM

Quote:

Originally Posted by Caseyc

Well, I just got this new to me 83 240D, and the AC isn't blowing cold at all. The car is in excellent shape and is 95% original (After market battery, driver window switch, wiper blades, and headlights are the only non OE components I could find) .

I just dropped it off today at my local Benz shop to get all preventative maintenance done. AC recharge with 134 is on the list. I asked about converting it over to R12, but the shop owner said he doesn't carry it as it could result in a hefty fine. He looked my system over and noticed it has been converted over to 134 by the PO. He plans to diagnose for leaks and/or faulty components. The fan seems to blow surprisingly hard, and the heat works exceptionally well, although there is a slight leak coming from the heater valve.

How hard it it to check or clean the evaporator? My condenser looks great from what I can see. I don't mind spending a lot when it comes to the AC in this car as long as it does what it's supposed to. The R12 sounds very appealing, but how do I go about finding some without incriminating the shop? If it's illegal to use here in Colorado, I would suspect the individuals that have it, keep it for themselves or select high paying customers.

I fully intend to keep this car till I'm long gone, and will little by little work towards a full restoration while using it as my daily driver. By the way, thanks for all the help.

Kind regards,
Casey

Either the guy at the shop doesn't know what he is talking about or he is feeding you a line because he doesn't want to deal with r12 in his shop. I'm guessing the latter. It is illegal to produce r12, not to own it.

You should be able to find some r12 on your local Craigslist or eBay but it is not as simple as just putting it in. Perhaps if you brought the r12 to the shop they would fix the system and charge it with the r12.

uberwasser · #18 05-31-2014, 04:32 PM

Question that I've asked before without an answer, so I'm asking again since it's related...

Is there anything that needs to be done, besides a full flush, on a system that's been converted to R134a to roll it back to R12? Are the seals, oils, etc used on R134a backwards compatible, as it were?

Graplr · #19 05-31-2014, 05:54 PM

Quote:

Originally Posted by uberwasser

Question that I've asked before without an answer, so I'm asking again since it's related...

Is there anything that needs to be done, besides a full flush, on a system that's been converted to R134a to roll it back to R12? Are the seals, oils, etc used on R134a backwards compatible, as it were?

I'm fairly certain the seals are backwards compatible (you can use the green ones with R12). As long as you are using the synthetic oil I believe you don't even need to change the oil as it is compatible with both refrigerants. The only problem with that is you are guessing as to the amount of oil in the system. If you want to do it by the book and use R12 oil then I would flush it all, change the orings, put a new expansion valve and a new drier in. If you do a flush you are going to crack most lines so might as well put new orings in.

ROLLGUY · #20 05-31-2014, 05:58 PM

Correct about the Orings, and Ester oil is compatible with both 134a and R12. If PAG is in there, it all needs to be flushed out if you are using R12.

uberwasser · #21 05-31-2014, 06:32 PM

Thanks folks. I guess I'd also have to get the fittings (R134a uses schrader valves?) changed.