R12 to R134a

[sldan]

1991 300SL A/C conversion to R134a. Has anyone had the conversion performed at a dealer and if so how much did it cost?

I performed a search and there is a lot is chatter about the conversion pros and con.

SLdan

[BDBENZ]

Hopefully some one will be able to help you with the 300 SL but my 87 560 Sl was converted by Crown. They also needed to install a new condenser. It was done according to MB specs and new pag oil installed with 2 pounds of R134A. I know there are a lot of pros cons, but my system will flat freeze you out. Yesterday with the 90 to 92 temps and 80+ percent humidity, it was ice cold with 45F vent temps. I was checking because I had installed new o-rings on my compressor after the old ones failed. That is the only bad point; MB does not recommend the change out of o-rings. Maybe they should hold up but with my 16 year old seals they did not. I only have 54,000 miles on the car. Regardless, it works great when everything is sealed up. The cost was around $700 last year. I resealed the compressor myself for $28 and a new recharge. Good Luck.

P.S. Why are you recharging and thinking about the change?

BD

[sldan]

Hello BD,

Thank you for the reply. My plan is to have Crown check the system to see why the R12 level dropped and if no leaks just recharge with r12 and let if go at that. The idea being that the gas level has dropped over time to a point where the system does cool enough. The compressor runs and there are bubbles in the site glass.

If there is a leak then I will convert to R134a. The 1991 300SL required a new drier, a couple of fittings, and the labor to flush and recharge. Plus find and repair any leaks. The conversion may be around $325.00.

Your point about the O rings is well taken. If work is to be done then it seems to be the time for new compressor O rings.

The car has slightly over 52K miles and worth keeping inexcellent condition.

Were you at the All German Car Show this month at the Windham in Dublin?

DT

DL

[BDBENZ]

sldan,

I was not at the show this year, but did make it last year. I was out of town. I enjoyed meeting everyone and talking cars. I plan to attend in the future. Did you enjoy the event?

BD

I'm very happy with the R134a system in my '83 380. I have not done a temp check but it is nicely cold no matter how hot or humid. (and it has been very humid here in New Jersey). Sometimes it seems to take slightly longer to get cool than my '02 Volvo but even that is questionable.
My car was converted before i purchased it so the choice was not mine and i dont know what it cost. I was grateful it had AC at all
No complaints with R134a.

[sldan]

Keith,

Thank you for the reply. I am confident R134a will do just fine if the conversion is required.

Just a side note: I spent 39 weeks at Fort Monmout, NJ in 1966 and loved the area. Seems like a million years ago.

SLDAN

[maheath]

R134A works well in a system designed for R134A. R134A may work fine in a system designed for R12 in Ohio or New Jersey. R134A in a system designed for R12 IS NOT SUFFICIENT in Texas (or probably any other "hot" state).

Just so you know.

[jcantor]

Mike,

I understand what you are saying about the Texas heat but keep in mind that while this year has been very cool, last summer in NJ had a record number of 25 or 30 some days over 90 deg (most over 95). My '87 560SEL which was converted to 134a before I got it - probably by the original TX owner BTW - did just fine at keeping everyone comfortable.

jlc

[maheath]

It's not uncommon for Austin to have that many days over 100. We just came off of a two week stretch where the high ranged from 103-108. I can't even drive with my top down at those temperatures.

[BobH]

SLDAN,
I had my 1990 300 SL converted in June of last year. I had it done in concert with some other work, but the costs for the R-134 changeover kit, incl oil was $58.00. The R-134 was $20.00 and a new fan switch to better accomodate R-134 was $47.22. The labor rate was $65.00 per hour and I don't have a breakdown because of all of the other work performed. It would appear that it was less than 1 hour.Since that date and traveling another 13,000 miles the AC has operated super. If the car is really hot, I might set the fan speed at 2 or onrare occassions 3. After about 15 minutes, I usually turn in down to 1. I rarely use the automatic setting because its a little too cold even when set at 72. BTW, summers at the Jersey shore are pretty hot.

Bob

[sldan]

Bob,

Thank you for the very informative reply.

It was god to hear from a 300SL owner on the matter.

I will ask about the fan switch when I take the car in next week.

I am glad to hear the converstion has worked out.

SLdan