I own a 1989 245 that has not been converted to R134a and was wondering why not keep the original R12 vs swapping all the hoses, drier, O-rings, condenser, compressor, etc that would be the "right" way to do a 134a conversion. R12 can still be purchased on the internet. I assume there must be AC specialists out there that have the correct hoses to pull a vacuum on these older systems?

I do have a complete donor car that does have the R134a set-up, but I am hesitant to undergo the swap considering how difficult it must be to swap out the condenser under the dash. To do it correctly I assume the condenser needs to be swapped which means dash removal?

Is there a reason most people just swap to the easier to get, less expensive 134a or are those the main reasons?

 

There is no reason to change the hoses. That was late 80s rumor and it is simply not true. I would recommend that you remove all of the components and install new O rings, including a new drier. While apart, flush the system.

To flush the compressor, pour PAG oil in the outlet and have it come out the discharge. After a few cycles, you have PAG oil.

When you do charge the system, be sure to pull a vacuum for about 30 minutes. When you are satisfied, charge the system to about 90 percent of the R12 values. Also make sure that you add the proper amount of oil before you vacuum and change the system.

Going with R12 is not a good idea.

 

the standard conversion procedure is to flush the system with mineral spirits aka paint thinner, to remove all old oil. then blow that out with dry compressed air, then replace the dryer, orifice, and o-rings, pump the hard vacuum, and hold it for at least 60 minutes, then recharge with suitable oil.

 

The component under the dash is the evaporator and the component in front of the radiator is the condenser. If you can get R12 it is more efficient but most states outlaw it and most AC service businesses don't want to handle it anymore. There is a procedure to do the conversion and the important thing is to flush the old oil out which they sell a flush kit to do.

 

R12, is hugely expensive, like $200-300 to fill an average A/C system IF you can find it and someone to want to do it.

 

you *could* use HC12 aka Envirosafe, Freeze 12, and various other names.... this is a blend of propane and butane, which has refrigerant properties quite like R12. its illegal in most places to use a hydrocarbon refrigerant in an automobile, but some folks say this is juts because DuPont lobbied to outlaw it so they could sell their proprietary fluorocarbons. there is some explosive potential, a leak in the evaporator could potentially fill the cabin with an ignitable mixture if there's inadequate air turnover in the cabin.... but R12 and R134a are also flammable and in fact quite toxic when burned, so... caveat emptor is all I'm saying.

when I've seen it used, its worked quite well.

 

oh. if you do put HC12 in the system, LABEL IT WITH A STICKER OVER THE FACTORY R12 STICKER, and assume that no legit air conditioning service shop will ever want to touch the system again as it will contaminate their extraction and recovery systems.

 

I started using Fosty Cool this yr. They make R12a which is compatible replacement for R12. What I like is the low head pressure. Just done a conversion on an 12 honda civic with Frosty Cool 134 and its ice cold and the high side is less than 200 on a 100 degree day. Im about to do my Volvo but going to put a new condenser with it.

 

So, the evaporator just needs to be flushed thoroughly not replaced? I have also read that the AC hoses will need to be replaced with a 134a conversion with specially lined one as the molecules in 134a are smaller than R12 and will eventually permeate out through the walls of the hoses.

Seeing that I have a car with a complete 134a system as a donor I may as well just complete the swap with ALL, minus the evaporator, parts I have heard of people using propane on a Landcruiser forum and isn't it used in commercial applications? I think I would stick with something "approved" for automotive use just to be on the safe side.

 

Dave Burton has a good write up on this. But I believe the 134a used a different and bigger evaporator. But its alot of work to replace.
I have used propane in my 1990 Volvo with good results other than it freezing up on long drives. In town its ice cold at stop lights which you wont get with 134a unless its a newer car. Propane has been used for years as refridgerant. Names R12a; R290; ect. Duracool, Redtek, Envirosafe, are pretty popular. I have no problem with it other than its a hit and miss if you use straight propane. Plus your head pressures are high like 134a.
Personally if it was me, I would stay with your plan of changing over then use one of the R12a or Frostycool 134 in you system. Frostycool will be lower head pressure which your compressor will live alot longer. I will post a couple of links for you, then read up.

 

Dave's Volvo Page - Volvo 240: Classic Auto Air Retrofit

Using Propane in Volvo AC - Turbobricks Forums

Wholesale Refrigerant - Cheap R22 Freon, R22a, R410a, R12a, R134a Replacement

 

I just read the page about the retrofit. Wouldn't it be easier and less expensive to just buy an S60 with modern AC?

 

Yes Im sure. I wasnt refering you to do the retrofit. I just thought you could learn some things from his experience. Hate to see you go to alot of work to change everything over and not get good results. I do have a 1993 Volvo 240 that Im gonna repair the Ac on and I could let you know how it compares to my 90.
My 90 Im installing a new condenser (modern parallel) then cleaning the system out, then filling with Frosty cool. Im trying to get mid to high 30s in 100 degree day with high humidity.

 

let us know what you do and the results. It helps others. Thanks

 

I've run the math before and on a 100 degree day with the fan on high, there isn't enough capacity in any system to blow 39 degree air out the vents.

Now, turn the fan down on low on just above and yes.

Those old 240s had very inadequate air conditioning. They were sized for a Canadian or Swedish climate and did not have enough capacity to adequate cool in the hot southern states. I know this because I am a dealer and experienced these cars being inadequate until a new system was installed in 1991. Volvo basically used a GM system and upsized both the evaporator and condenser. There used to be a retrofit kit but I am not sure if anyone still sells it.

You can put a larger condenser in an old R12 system and it will help some, but the evaporator needs to be balanced in size, as well.

 

the 940's have a much better HVAC system. moves more air, yet is quieter. the fan is on the passenger side behind the glovebox, so easy to replace.

 

Gotcha, I appreciate the info. I have to say when I got my 240 four yrs. ago the AC was a joke. The PO had new compressor and had it changed over to 134a. I added a condenser fan and a new drier. Then tried 134a with small improvements, then went to propane. Which is pretty nice other than it freezing up on me going down the highway.

Next step is the condenser which is a little bigger, then will put frostycool r12a in it. will keep you posted. Sorry didnt mean to highjack this thread but believe we are both after the same goal.

 

Yes, the 940 system is larger and was modernized for hot southern climates. That's the way to go.

 

I had our 1989 740GL out today to run some errands. As I mentioned I had replace everything except the evaporator and one of the hoses. This rebuild was maybe 10 years ago after I blew the condenser. Prior to that I bought the 134a conversion kit and had done the change from R12 to 134a. That was maybe 15-20 years ago. So todays temp was 97* with about 70-80% humidity. Here is the reading at my center ducts so the system still runs OK. And by the way I need to usually give it a shot or 134 each year as summer arrives.

 

Im not saying it cant be done but think in a 240 would be hard to get them results. I had one of my 240's that we put a new compressor, drier, and condenser on they were all 134a compatible. My brother lives in New York your high was 88 today and humidity was 58%. Which is still hot.
Anyway, back to the 240 we tried different brands of 134a never got it down in the 50's vent temp. I wish I could get that with 134a its alot easier to buy than ordering the fridge.