Hello,
Need some advice from those who have done an R-12 to R-134 AC conversion. What's best, doing it yourself with the kits or paying someone to do it? What's an acceptable price? I've had one quote of $650 to make my 90 F150 XLT Lariat Supercab compliant with new refrigerant. Seems high to me. I'm interested in this cause it cools now, but never gets really cold (not cold enough to suit my wife anyway...not an uncommon situation, I'm sure). Thanks for all feedback.

tim mcalavy

 

The best time to convert is when your system loses all of the R-12 due to a leak or failed evaporator/condenser/compressor. If you need your R-12 topped off to get the temp down, spend the $75 or so and do it. If the system must be opened up, definitly consider converting. To convert you must change the accumulator and replace the compressor lubricant with PAG or ester oil. The old lube will not dissolve in R-134. If your hoses are in good shape they can be reused since the old lube tends to plug up the pores in the rubber. If getting new hoses be sure and use the "barrier" type which is designed for the smaller molecules of the R-134. Replace o-rings with the blue or green type. While you are in there, change out the orifice. For $650 you can buy everything you need INCLUDING a vacuum pump and charging manifold. You will also have to put on conversion servicing ports; they just thread on to your existing bicycle valves. An average wrench bender would have no problem doing the job and charging the system. One word of caution; results tend to be mixed. Some systems do not cool as good as they do with R-12 and also, since the condenser tends to get a little hotter with R-134, some vehicles tend to overheat in traffic and require a bigger radiator. Hope this helps.

 

This is true. I did one of those do it yourself conversion kits. The AC is nice and cold, but not as cold as it was with the R-12, but it's better than nothing. Also, the car oes seem to run warmer than it used to. I have a 120K on it and it still has the original rediator, when it's time to replace it I would probably go with a larger one. I had to convert my system since I took a stone in the condensor, figured I might as well change it now since Freon is getting more scarce. Conversion cost to me was $75 and that included the evac by an AC shop.

 

My mechanic has converted 3 of my cars to R134a. Cost = $110. He did not replace the accumulator, but he did, I believe, adjust the cycle times since the compression is different for R134a. I also have mixed feelings on the "coolness". It does a decent job (27 degrees lower than ambient temps) and my engine does tend to run warmer. I purchased a vehicle that had already been converted and did not cool well. Took it to my mechanic and he said that it had too much refrigerant. He removed some and the A/C runs great. Cools an extra 10 degrees lower than before.

Slik

 

I've converted 2 Ford trucks and one Geo Metro. Go to Pep Boys or one of the other parts houses and get a kit. MAKE SURE THE KIT HAS "ESTER" OIL< NOT "PAGS". R12 systems used a mineral oil that is NOT compatible with PAGS. PAGS is only for systems that used R134a FROM THE FACTORY !!! No matter how hard you try, there'll be some remnants of the mineral oil in the system. Ester oil IS compatible with minearl oil.

Now that I've hammered that point. Get the kit. It'll have a hose, adapter fittings and should come with some R134a. My F250 holds 2.5 lbs of R134a. In a conversion the instructions tell you to use 80% as much R134a as you would R12. Somewhere on your A/C evaporator housing should be a decal with the OEM refrigeratn / oil ammounts.

To do the job right you must replace the accumulator.

If it was mine, I'd have the system checked and if there's not leaks found and just needs a pound of R12... that's what it would get. When something fails (major leak , compressor dies, etc..) then that's the time to convert. By the way... $650 is OUTRAGOUS. Consider many other estimates. (Heck.. for $650, I'd come to your house and do it!!!) I did my truck for under $100. Expect to pay maybe $250 to have it done.

DM

 

Right you are sir! Had my AC system pressure checked and discovered a bad seal/O-ring. After some running around, found an honest AC man and had the old R-12 system changed over to R-134 for about $250. Not bad, considering they had to replace the seal, accumulator, clean and flush the system, etc. I'm happy. The R-134 doesn't cool as well as R-12 in stop and go stoplight driving, but seems to do a better job running down the road with plenty of air circulating over the condenser coils. Thanks for your input to this thread.

 

My F250's A/C is not as cool at idle, either. I may put an aux electric fan on the front of the condenser to help get rid of the increased heat generated by the R134a system.

$250 ain't too bad... A friend of mine has a shop near Wash. D.C.... he gets $650 for a job similar to yours. Now that it's been converted, it'll be cheaper to perform any future repairs... R12 is VERY expensive.

 

I converted mine with only a kit from K-Mart that costs about 30 bucks. So far it's been around 6 months and going strong. The only downside is that the new refigerant isn't quite as cool in start/stop driving than on the highway. For 30 bucks though I can live with it. By the way, my truck is an '88 F-150.

Mark