Learning me running an R12 AC system these days

The Bavarian horseless carriage has an r12 ac system. The system has been opened up, so I plan on replacing the o-rings and taking it to a shop to see if it will hold pressure.

Should I plan on converting it to r134a, or is it possible to get r12 still? I've heard r12 still exists in recovered form at various shops, but that it's very cost prohibitive.

What would GRM do?

My crx was designed for r12. Works great with 134, even in a black car.

R134a wouldnt be as efficient as r12 with the old tube finned condenser. Switching to a parallel flow condenser would be better.

Not looking to spend a lot of money, as per typical GRM mindset.

tpwalsh wrote: My crx was designed for r12. Works great with 134, even in a black car.

Did you do anything to convert it, or just load it up and hope for the best?

Did this way back with a 90 Miata. Expect about 75% of the cooling power you had with R12.

I had a habbit of driving with AC on and Top down, and with the R134a it was never the same. Top up, on a hot day, in traffic, I was happy to have the 134a.

Did the swap on two cars, totally lazy way too. There was nothing in the system, screwed in the adapter and shot in a can of 134. Worked well enough, not frigid but cold enough to make the car comfortable. Did this on a 91 volvo 240 and a 93 MR2. Volvo needs a shot every few months, you know when by the compressor cycling.

I did the same as porschenut with an Achieva, just put the R134 in. Cooled pretty good, even in the middle of summer. After about a year the compressor started making noise, traded it shortly after that. Of course on that car GM thought it was a good idea to bury the dryer in the pass side fender, where you could barely see it. Thus I didn't want to try and change it, so I went with the lazy method.

Edit: My Dad just picked up some R12 cans for his Dakota, so they are still out there. The guy has a 30 lb container as well.

I put some money into the A/C on my truck maybe 10 years ago. The compressor had locked up. I stayed with R-12, which was quite expensive but still available. New compressor, receiver/dryer, evacuate, pull vacuum, oil and recharge. The system worked great. I had A/C in the truck!

Then, the rebuilt compressor I bought sprung a leak after about 9 months, and let $250. worth of refrigerant off into the wild blue yonder.

If I do it again, I'll go with R-134.

Taiden wrote: Not looking to spend a lot of money, as per typical GRM mindset.

In that case, re-seal it, put a couple of cans of R134a in it and see what happens. If you have the tools, see if it will hold a vacuum (leak test) before putting the refrigerant in. Even better would be to put the refrigerant in while the system is under vacuum.

At this point I think using R12 costs more than doing a "proper" conversion to R134a. But that's just a guess. 75% of the cooling power should be plenty for you, unless you like to store meat in the car or drive with the windows down in the middle of the desert.

Ian F wrote:

Taiden wrote: Not looking to spend a lot of money, as per typical GRM mindset.

In that case, re-seal it, put a couple of cans of R134a in it and see what happens. If you have the tools, see if it will hold a vacuum (leak test) before putting the refrigerant in. Even better would be to put the refrigerant in while the system is under vacuum.

Whaaa? I would never think of putting refrigerant in the system without vacuuming it down and checking it for leaks. But that's just me, I guess.

Has anybody tried the R12 substitutes on the market? Something like this Freeze 12 stuff?

http://www.ebay.com/itm/FREEZE-12-R12-SUBSTITUTE-FREEZE-12-3-CANS-/310390724252?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item4844ba969c

I had tried to use it on my old Benz. It gave me cool air for a short time, but that system had some bad leaks and it didn't stay working very long. So I can't say one way or another, really.

dculberson wrote: Whaaa? I would never think of putting refrigerant in the system without vacuuming it down and checking it for leaks. But that's just me, I guess.

Well yeah... that's the right way to do it... but not everyone has a vacuum machine and the fittings to connect it to the system, whereas anyone can buy a $25 recharge kit from Pep Boys.

Plenty of R12 still on the market, just look at the many cans of it listed on ebay. Gotta have the green licence to buy it, but that's an easy test to pass.

The roughly 75-80% efficiency comparison between R134 and R12 is for two systems in perfect condition and optimal balance. Old ones that get switched usually weren't anywhere near optimal, so the switch to R134 usually ends with them working better than they had been in the latter years of their R12 operation.

I've converted a number of vehicles myself, using the generic kits sold at auto parts stores and walmart. Vacuum them down, add the oil, add the R134, enjoy the cool. The hardest part is fixing whatever went wrong to begin with that caused the R12 to leave.

Make sure you use O-rings designed for refrigerant, I use the green ones from harbor freight and have had good luck with them.

I did an R-134 conversion to my minivan like 2 years ago and it works great, I have to add a can every summer, but I'm assuming that's the evaporator I don't feel like taking out the dash to get to.

So would I be better off snagging this:

$14.00 specific "o-ring kit" for my car

OR

$17.75 universal r134a conversion kit

Make sure the hoses are good too.

DoctorBlade wrote: Make sure the hoses are good too.

Yeah, I just need a place to start from. I don't really want to replace anything twice. The previous owner starting taking apart the evap under the dash. I have no idea why, he won't return phone calls. So it may be bad, but I know for sure that the system has been very open for a while. If I spend $15 to find out that I need $500 in repairs, I'll just leave it.

The neat thing is, R12 is a helluva lot cheaper than the stuff we're going to be replacing R134a with, since R134a is going to be phased out soon.

We were told that the new stuff will be 10x more expensive than R-134a. R12 prices are pretty much stagnant at ~80-100 bucks a pound, for now.

Test the system with just a wee bit of r12 then top it up with Nitrogen or even helium (ballon kit from wally world..) then sniff for leaks or just wait and see if it looses presure.

Several years ago Advance was closing out the Dupont 134a for just a few dollars a can. I cannot believe I didn't buy a whole case.

The local AC guy told me it wasn't even worth dicking around with r12 as it was 200$ to fill the system with 2.2lbs of freon. Another issue is that not all AC compressors are convertable, I hear the York(pos) on my mercedes isn't able to be converted to 134a. I don't know AC though, I already have dual 80s on my car(roll down the windows and drive 80mph).

benzbaron wrote: Another issue is that not all AC compressors are convertable, I hear the York(pos) on my mercedes isn't able to be converted to 134a. I don't know AC though, I already have dual 80s on my car(roll down the windows and drive 80mph).

My only knowledge on this subject is a local Volvo 1800 guy converted one of his cars to R143a, York compressor and all. He said all he did was charge the system. Nothing else. As far as he was concerned, the compatibilty issue was B.S. Sounds fishy to me, but it worked for him.

I'd use the substitute products. An old Euro car is going to be real marginal on cooling even with R12, so get the Freeze12 or whatever they call their mix of propane and butane these days.

Then don't smoke while you are working on it.