I have a 1988 Ranger I'd like to convert to R134a. Has anyone done this successfully? Is it difficult? Any recommendations on dos and don'ts, procedures, necessary tools.

Thank you for all responses.

 

I also have a 88 ranger, i just did a conversion and i am VERY pleased. I got one of the kits at autozone, $48, which included all the R-134a and oil. It also had a gauge to tell how much was in it. First you need to flush the system of any old R-12, might be able to get a garage around you to doit for free.(they can sell the stuff for $90 a pound) Once thats done check the o-rings aroud the compressor, they might be fine, but if theres doubt change em, dont want to waste fluid. Youll have to convert the fittings, to do this find the high pressure side (on the left side near the battery area) attach the fitting for that, then find the dryer, the black round thing close to the plastic enclosure on the left side. It will have a fitting on there too, attach the fitting for that side. Make sure that you tighten the low end fitting otherwise itll leak. Also i tried to get only get a converter fitting set and the low end wasnt the right size. After that tuen the vehicle on and the ac on max and fan on high. Then shake the bottle of R-134a(they also have the oil in them) and attach it to the gauge. Dont screw in the puncture needle until youve attached it to the low end fitting. Then screw the screw in, until it punctures and back off until it starts filling. Try not to go in the red on the gauge(tighten less, loosen more). Youll notive the compressor cyclying on and off, thats normal. Wait until the bottle is empty and repeat to the other 2 bottles. The whole procedure takes maybe an hour, and it works REALLY WELL. If theres anything i forget just yell at me.

 

i am looking at doing a conversion too but did you have to change the compressor oil too.

 

No, the mineral oil doesnt mix with the R-134a, so it just sits at a low spot in the system, doesnt do any good, or bad, but if you have it drained then it might come out with it. The kit's bottles include the new oil in them, so you dont need to worry about that. its pretty simple.

 

If you didn't change the dryer, the oriface, put in barrier hoses, flushed the system, and changed any O-rings, then the 134a conversion won't last long. Your best bet is to put in one of the R-12 replacements in it.

The dreaded black death will soon happen to your compressor if you haven't changed this stuff as the 2 oils mix and break down the rubber in the hoses and O-rings.

 

Danger, what was the name of the product you used for the R134a conversion?

 

http://www.sadik.net/nissan/howto/ac_r12.htm
I you go to this website itll tell you the directions and why you can use a closed loop system.
I used the COMPLETE RECHARGE & RETROFIT KIT made by Quest it has a COOL ZONE logo on the front as well. Like i said i got it at autozone for $48.
Goofy-i did alot of research on the web and although it would optimize the system, recent research has concluded that you dont have to replace the parts. The oil is different than the regular, and the old mineral oil will not mix with the R-134a, only the new oil will. I also learned that the chemical makeup of the mineral oil helps seal and protect the rubber hoses. It is possible that you could have a very small leak because the R-134a molecules are smaller, but from what ive read and heard it isnt a problem.
I heard a rumor that the newer R-134a is a little different from the stuff that first came out or that something was added to allow it to work with the R-12 components.

 

the proper way to change the oil in the system is to run the new oil thru the system with R-12 recover and repeat until the percentage is 5%(checking with spectrometer) then evacuate and charge with R-134a.
Part of the problem with converting to 134a is the older hoses and seal are not as gas tight as the new stuff designed for 134a. the other is the older R-12 components are smaller in capacity and will suffer cooling loss. R-134a has less btu capacity per pound than R-12.
134a also seperates and leaks its seperate components, so you can only get away with topping off the charge a few times.
134a has not changed but the oil that is use with it has. the oil is still very hydroscopic and absorb moisture rapidly, part of the reason for new desecant.