Converting A/C to R132a?

[Dooley Dude]

I last had working a/c in my truck many years ago, when I put in a new compressor and receiver/dryer, pulled a vacuum and charged the proper amount of oil and R-12. Worked great for about 9 months, then the compressor (a cheapie reman unit) leaked out the charge.

I would like to fix it again, hopefully with better results, converting to R132a. Other than a new compressor and receiver/dryer, what do I need to do to make the current system work with R132a?

Edit: I guess I mean R134. Whatever refrigerant is commonly used these days.

[S10Fan]

I've talked to folks that have used this http://www.freeze12.com/ with very good results. The first thing to do is find the leak, probably need to replace the reciever dryer as well.

I've decided to go with a system from Vintage Air. By the time I round up and buy AC parts I'd be money ahead with a kit.

[Buick455]

Do you mean R134a?

You can just drain and flush the system and use a new dryer and orifice tube (check into the variable one) and it may work. For the best results it is recommended to change the hoses, dryer, and get a new pump and flush out the evaporator and condenser, I used alcohol.
I changed over my large IH 886 tractor and 92 Chevy with these changes and have worked well for years. Some recommend a larger condenser but in my cases the original ones work fine.

[Dooley Dude]

Does anyone know the precise location of the orifice tube?

I guess at this point, I'd be wise to replace the hoses as well.

[Slonaker]

The orifice tube on my '86 is in one of the aluminum tubes bolted to the passenger side fender. There is a connection that you open there that holds it. If it comes out looking dirty, you should flush the whole system. It works kind of like a filter, so if it is dirty, the whole system is contaminated.

Slonaker

[westofb]

Orifice tube should be in the lower connection (evaporator) going into the hvac box. Break the connection (it is the smaller hose that runs from the evaporator to the condensor) and you will see it inside the lower evaporator tube, use needle nose pliers, kind of twist it while pulling on it and it should pop right out. I would recommend replacing it (about $3.00 or less) as well as the compressor, and the hoses. I bought an 134 retrofit kit which includes all the o rings as well as the 134 fittings. For what it's worth, I have heard both, that the R12 o rings are not compatible with the R134, just fir piece of mind I changed all them out to the R134 green colored o rings. Besides I am sure some of the old ones were bound to leak, just from their age. Now a days, even 134 is getting expensive!

[gchemist]

Don't forget the R134 semiparallel condensor.