Hello all,

I have a 91 that I just bought. The condenser is missing but the rest of the ac system is still intact and in good repair. I was going to have the conversion done to r134a. Have any of you done this? what are the pros and cons? I know the new stuff is cheeper and the old r12 is colder, but is it enough to really make a difference? Would love input from prople who have done the conversion and can compare them for me.

 

I did a drop in replacement. It does cool the truck but is not as good as R12. On hot Texas days when the truck has been baking in the sun it takes a bit to knock the heat down.

If you can get your system sealed nicely then buy the 12 oz cans of R12 from Craigslist.

 

Duracool, or a homemade copy of it will cool as good as R12, and better than R134. It is a mix of propane and isobutane. Flash point is actually higher than r134A.

I Mix my own. One 8 oz can of iso..... mountain stove fuel, and 12 oz of coleman propane. (found to be drier than most.) Takes about half the weight as the freon charge.

Have installed it in several old systems. You can hang meat in any of the cabs involved.

 

I didn't necessarily convert the "right" way but my truck was missing the compressor when I bought it. Once I got everything hooked back up how it was supposed to, I bought the little pack of conversion fittings from the local autoparts store and some of that diy r134a stuff. She held a charge and cooled excellent. Constant 40 degree air blowing out the vents.

 

My truck was converted long ago, there is a sticker under the hood near the low pressure charge port. I did top it off with the Walmart r134a can and gauge when I got it because the ac would cycle constantly or not come on.

For the last couple thousand miles it's been very cold. Not as cold as say my Subaru with perfect weather stripping but very acceptable here is so cal.

 

I changed everything in my system except the hoses when I converted to r134a. I did put two small 8 or 10 inch pusher fans on the condenser. It cools well, hasn't lost any charge in over two years either.

Since I am a smoker I'm really leery about putting propane or any other type of fuel in the system even if it works a little better.

 

I am very interested in this. What do you use for oil? and how do you get get the mix into the system ie: fittings.

 

Like this?
Possum Living: Propane Refrigerant for Automotive Air Conditioning

 

Yes, that's a pretty fair description.

If you can find a 14.1 oz can of Coleman propane, and an 8 oz can of isoheat (80%idobutane, 20% propane) stove fuel, it'll make a 22 oz charge within a coupla percent of the ideal mix. Into an evacuated system, put the stove fuel in first, then the propane.

If you pre-mix it. (I make up a double or triple batch into an old R12 bulk container with a decent valve welded onto it.) you need to withdraw it from the tank inverted, or it'll distill into it's components on you.

 

sounds pretty easy Thanks for the info.

 

I converted mine a few years ago, see here: https://www.dieseltruckresource.com/...system-313221/ . I have to disagree with the ones that say it is not as cold as R-12, mine will freeze you out and I don't exactly live in a place that is EZ to cool...Mark