The last couple of days in So. Cal. have been over 100 degrees and my A/C seems not quite up to the job. With the fan on low the air gets noticeably cold, but doesn't blow enough of it to cool down the cabin. If I turn it on high or auto, it starts off cold then gradually warms up to just mildy cool, it that, after about 3-5 minutes. In cooler weather it seemed to be adequate, but now I think I have to do something. One of the local independents with a good reputation is trying to convince me to convert to R134. He says it's a simple conversion and the system will run colder than with R12. I'm a bit suspicious about this as everything I've heard about converting to R134 says that the two systems are not generally compatible.

To inspect, evacuate, fill and leak check my system with R12 he wants $150 labor and about $55/lb for the freon. Does this seem reasonable? If not, can anyone recommend a shop in the area? I live in Monrovia, about 6 miles east of Pasadena, CA

Thanks,

Gary

Stick with the r12. You may just need to add a little. Get someone to put some gauges on it to check the pressures and add as necessary. You will regret going to 134 in this car.

__________________
Jim

They were marginal under High thermal load to begin with ..

Check the eye-sight glass .. they are a decent indicator on R12 systems...

Also, blow out the condensor....

See if your recirc function is working. You could be a pair of actuators away from enjoying/surviving the summer.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I would recommend sticking with the R12. Had to have the evaporator replaced last summer in my 1992 300E (pulled dash and all the fun that involves- for $1700). I ws out of town so my mechanic couls not reach me to see if I wanted to go the R 134 route so he kept it a R12 system).

What luck - it is in the mid 90's here in orlando and I am still freezing with the A/C to the point that I have to adjust the temp. So stick with R12 in my opinion. BTW I had him replace all the actuators and heat core as he had the dash opened up.

Good Luck

Sixto - you wrote "See if your recirc function is working. You could be a pair of actuators away from enjoying/surviving the summer."

Would you mind elaborating on this a little? I've only had the car a year, and this is my first Mercedes. How do I activate or check the recirculation function (I don't have the owner's manual)? None of the push buttons for the a/c controls give any indication that they recirculate the air. If they're faulty, what's the cost, and can I get at them to replace them myself?

Thanks for the help

Gary

Does your car have a recirc button above the ACC control panel? The symbol is something like 3 arrows end to end forming a circle. If you press it with the AC on, it'll stay in recirc for 30 mintues. If you press it with the heat on, it'll stay in recirc for 5 minutes. The ACC will also set the recirc mode based on internal calculations.

The acid test is to have create an odor at the base of the windshield and see if you can smell it in the cabin while the ACC is in recirc mode. If the odor is distinct in the cabin, the fresh air flap isn't closing.

I don't know where the actuators or fresh air flap are in a W124. They're right behind the glove box in a W126.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Thanks Sixto, I'll check it out tomorrow.

Anyone else know where the actuators are located on a W124 and how to get to them?

Gary

I'd also suggest sticking with R12. I have done so in my '92 300e and the a/c air from the vents is freezing on max setting.

I also have '94 E500 with new a/c evaporator, receiver dryer, seals, fresh recharge....and the a/c air from the vents does not appear to be as freezing cold on max setting vs. the '92 300e's.

-fad

There is no chance changing the refrigerant to 134a will make it cooler. The only way it would be cooler would be if you were real low on R12 and filled it with 134. The system full of 134 would cool better than a 25% R12 system (sometimes even more).

The early 300Es were the worse of all models to convert (by that I mean they worked the worst - not that they were the hardest to do. They were the first MB we quit converting. The first car in general were 911 Porsches.

The recirc door element is one the back side of the evap and requires at least pulling the dash. The recirc door is partially closed by turning the A/C on and if this doesn't happen the duct temp will be 10-15 degrees higher.

If you wish to evaluate your A/C get a digital thermometer and see what your duct temps are. They should be atleast 40 degrees off ambient at 50mph or above and in HIGH blow.

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

like it or not, R12 is getting to be scarce commodity.

__________________
joel

Prayers bring forth enlightenment.

So don't give up what R12 you have.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I see a day when all other cars that originally had R12 will be in the wrecker's yard and only street rods, classic/ antiques and Mercedes will be around to use the stockpile of R12. Supply (larger than you might imagine) and demand (only us)will then keep the price down.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

I had to put a pound and a half of R12 in last month and it was $85 a pound. I called a couple of other places and it was the same.

I have heard that R134 will eat away at the MBZ A/C system. Something about the metal alloy.

__________________
R. Downs
1985 500SEL (260,000 miles) SOLD!
1974 280 SOLD!
1994 Volvo 850 Turbo Wagon (Yuppie Ice Sled)

"I know I have a Benz and they know it too." If you start bragging about it or shoving in people's face, you then become a Wally; especially to the girls.

Take your car to an reputable independent mercedes garage.

I was thinking about this earlier.

If one had an early W124 and wanted to convert to 124. Would it be possible to use the compressor, aux.fans, and condenser of the 94/95 models and get cold R134 ac?

__________________
2008 BMW 335i Coupe