AC R134 Conversions...

[ADP]

Brunhilda got converted to R134 from R12 before I got her.

It has been suggested to me by a pretty reliable source, that the increased pressure with R 134 systems is really hard on the stock compressor. Now my stock compressor leaks, so I've got to replace it with a rebuilt unit.

Since I'm a transplant to the South, I've come to learn how nice AC is in a car.

So, are there any compressor options that will work on my car that can manage the increased pressures? Has anyone run across the same issue?

I don't mind changing some other stuff out either, but I know that certain components are hard to get to and have been known to make grown men cry.

I also don't want to cause other problems by having a totally frankenstein system that really doesn't work.

Ann

[Mike D]

Replace with a "Sanden" compressor.

If you have the old "York" style compressor (looks like a lawnmower engine stuck on the side of your engine) you will need to get an adapter plate ($50 from any competent A/C shop) and possibly have the compressor hose ends changed. Replace the drier while you are at it.

It makes a world of difference. Extremely low drag on the engine. I had one on a tired 220D and I could run the air all day in town. With the old York I had to turn it off at stoplights and stop and go traffic.

About $300 last time I checked. Worth every penny.

[kalpol]

Originally Posted by ADP

Brunhilda got converted to R134 from R12 before I got her.

It has been suggested to me by a pretty reliable source, that the increased pressure with R 134 systems is really hard on the stock compressor. Now my stock compressor leaks, so I've got to replace it with a rebuilt unit.

Since I'm a transplant to the South, I've come to learn how nice AC is in a car.

So, are there any compressor options that will work on my car that can manage the increased pressures? Has anyone run across the same issue?

I don't mind changing some other stuff out either, but I know that certain components are hard to get to and have been known to make grown men cry.

I also don't want to cause other problems by having a totally frankenstein system that really doesn't work.

Ann

I don't know what kind of compressor comes in the older cars (York, I guess) but I had my 79 280SE retrofitted with AC (came from Europe with heater only) and used a Sanden R-12 compressor with R-134a instead of finding the original York. (I'm sure you can use the R-134 version too, I just got the R-12 because i found a new one on Ebay for cheap - i think it was about $170.) Works great (when it works, there are some unrelated problems with the installation of a leaky evaporator and blend doors sticking), and the compressor is fairly inexpensive, quiet, reliable, and very easy to replace. If you're replacing a York, you'll have to find a bracket, I think, and possibly the hose fittings to the compressor may have to be adapted to fit, but that should be it. I forget exactly what compressor but if you care I can get the part number off it this evening.

[ADP]

Originally Posted by kalpol

I forget exactly what compressor but if you care I can get the part number off it this evening.

Thanks, that would be helpful!

Ann

[alabbasi]

I've performed an R-134A conversion on my old Saab and it worked pretty well unless you were sitting in traffic. I have used R406a in my W108 and it tuned my fingers blue. Unfortunatly the car has a leak somewhere so it didnt last long. Now that i'm in TX, I really need to get my A/C fixed.

[kalpol]

Originally Posted by alabbasi

I have used R406a in my W108 and it tuned my fingers blue. Unfortunatly the car has a leak somewhere so it didnt last long.

Seems like R-406a and Duracool and all those work great until the ambient temperature gets above 100 or so, or thats just what I read - anyone have any insight? I have six or seven cans of Duracool that I was thinking about using but I found R134 on sale for $100 off so just got a 30# can of that to last me until doomsday.

[alabbasi]

I'm not sure what Duracool is but 406a is (as I understand) the only real drop in replacement to R12. It's a non flammable propane based refrigerant (not sure how that works either).

I ran it in GA, where it can but rarely goes past 100 degrees. I suppose I can test it here in TX and see what it's going to be like.

[magnumrick]

I am also planning to replace the york compressor in my w114 coupe with a Sandan unit. I picked up a new compressor already but was wondering what other items in the system need to be replaced. Will any dryer work? Where can I get the adapters for the hoses? The current unit is an aftermarket ARA unit installed in the early 80's.

[ADP]

Originally Posted by alabbasi

I'm not sure what Duracool is but 406a is (as I understand) the only real drop in replacement to R12. It's a non flammable propane based refrigerant (not sure how that works either).

I ran it in GA, where it can but rarely goes past 100 degrees. I suppose I can test it here in TX and see what it's going to be like.

Another possibility - interesting idea.

Its not the heat in Ga that gets you, its those 90 degrees days with 95% humidity. Are you dry or humid in your part of TX, Al?

Couple of years ago my budget daily driver did not have working AC - and never again.

Ann

[Matt L]

Unless your condenser has been replaced, you are much better off converting the system back to R12.

[alabbasi]

Dallas is Hot and Humid. Pretty Horrible in the summer. There was once summer that had a continuous month of 100+ degree heat.

[Mike D]

Originally Posted by alabbasi

Dallas is Hot and Humid. Pretty Horrible in the summer. There was once summer that had a continuous month of 100+ degree heat.

Yawn! Only a month? Shucks, summer starts here in April and continues until October. Yeah, yeah, "it's a DRY heat"! So's a blow-torch! 118 degrees will peel the skin off of a mummy.

Any good A/C shop will have a proper drier. About the only difference is whether the pressure switch mounts on the unit itself. A good A/C shop can either make the ends or knows a place which does it. If possible have the ends put on the existing hoses or new hoses made. Adapters are just another place for leaks. If you are converting to R134 you have to have the compressor ends replaced for the different type of valves anyway.

[Tom Drew]

I believe the 108's with the V8's used the Frigidaire A6 compressor, not the York.

[Benzcrusher]

That's right Tom it's an A-6 compressor. Later M117's used Sandens but the PS pump was also relocated. The Sanden has a larger diameter than an A-6.
Why don't you stick with R12.
I've used R134a in 2 of my 123's, the compressors start to leak after about 2 years and cooling is marginal. The blue wonder is getting a a fresh charge of R12 in about a week.

In addition to replacing the receiver/drier replace the expansion valve under the dash on the passenger's side. Don't overlook the 30+ year old O rings at the hose unions...

[ADP]

Originally Posted by Benzcrusher

That's right Tom it's an A-6 compressor. Later M117's used Sandens but the PS pump was also relocated. The Sanden has a larger diameter than an A-6.
Why don't you stick with R12.
I've used R134a in 2 of my 123's, the compressors start to leak after about 2 years and cooling is marginal. The blue wonder is getting a a fresh charge of R12 in about a week.

In addition to replacing the receiver/drier replace the expansion valve under the dash on the passenger's side. Don't overlook the 30+ year old O rings at the hose unions...

Thats the part that makes grown men cry... Or, in my case, makes my savings account cry because I'm not doing it myself.

I think I am going to convert it back to R12. I gotta get on it soon, it was hot today!

Ann