AC Convertion
 

Just bought a '91 300SE would like to know if there a larger condenser available to make the change to 134a actually work.
(I have 24 yrs in the ac/refrigeration field I know that a change from R-12 to 134a doesn't work all that well w/o a larger condenser, or heat exchanger.)

You need one of these:

http://ackits.com/index.cfm?fuseaction=Parallel

Its a custom installation, but the only non-OEM option, and THE ONLY option if you want good r-134a performance. You should be able to fit a pretty big one in a w126. I was restricted to the 14" one in my w123, but it still performs very well.

GregS
'84 300D, 175k
'90 300CE, 165k

A/C in W123
 

Hey just read your pstings, very informative!

I wa slooking at installing a complete W123 a/c kit in my 230TE 1985 - do we know of anywhere I can get hold of a COMPETE MB part listing for the whole shabang?

cheers

I swithched my 1989 260E to R-134 about 5 years ago. I did not change anything, except for the fittings on the hoses. Same condensor, compressor and everthing else.
After reading this post, I went to check air temp. at the dash vent.
No refill in the last 5 years, outside temperature, currently 88deg. and very humid Air temp. at the vents : 41deg.F.
I think you are looking at problems taht do not exist.
JackD

Hi - was that a reply to me asking about new parts for a 230TE a/c system?

Jackd is one of the few that I've read about that have converted a 124 car with perceived success.

The guys at ackits.com converted a 124 car using bigger parallel flow condensor, dual aux fans and several other things and threw their hands in the air.

Everything else I've ever read indicated that this was one of the very worst candidates for conversion.

Jackd is this 41 degree vent temp at idle or at 2,000RPM with pressures stabilized. The worst performance situation for a converted car is usually at idle plus 81 degree ambient is not much of a test. The temp where I am today is 105 F and I would absolutely faint to see 41 degree vent temp from ANY converted 124 car sitting at a traffic light in Richardson, Texas today.

Good luck,

The test I ran was at idle speed in my driveway. I don't remember having been caught in heavy traffic at 105deg (these conditions are fairly rare in our neck of the woods).
But I've seen around 95-100deg. in traffic where the inside temp. was cold enough for the fan to run at medium speed.
The W124 system is better than my wife's 2003 Accord. It cools more rapidly than the Honda does and cools much better.
JackD

Jack also lives in Canada. I want to see an R-134A conversion work in 105-110 weather in Arizona/Texas/etc.

I would not bet on it.

Do yourself a favor and keep your BIG 126 car on R-12.

The max temp. we see in our area during summer is about 100deg. Even at those temp. my system is totally adequate in all conditions, even in heavy traffic.
R-12 has been banned in Canada since a few years. Older cars with R-12 can not be refilled with R-12. They must be converted to R-134.
Jackd

Well that settles it - Jack didn't have much choice - as usual, the govt. had their say.

Jack - I'm glad the 134 is working for you.