is there any difference between the ac in a 89rs 5.0tbi and the ac in a 92rs 3.1v6 besides the hoses? if so what? so I can buy whatever I'm missing then take to the ac man>

 

Compressor oil, orifice tube, and possibly the evaporator size.

 

Accumulator, orifice tube and evaporator are the same. Reuse the evaporator only, after it's properly cleaned inside. Accumulator are O tube should be replaced due to age.

 

The SAME orifice tube for R-12 and R134A? No wonder the new ones don't cool very well. That's a bit if a surprise. The glide on the two gasses are like night and day. With R134A and a pre-EPA expansion rate, half the evaporator is wasted. Sheesh.

 

Both systems are factory R12, the parts are the same. So yes, I suppose you can assume a retrofit in this case.

 

Good call, ES. I suppose I shouldn't have assumed a refit, but most shops are pretty scant on R-12, and even the R-414B is getting pricey (and was really not intended for a mobile system), so the most common refrigerant of last resort is 134. It already suffers in performance just by its lower latent heat capacity, thus the comment on the expansion control.

You are correct in that IF R-12 or a good tertiary blend is used, the original sized tube would be more appropriate.

 

There is no more pure R12 available and any shop that has some isn't allowed to sell it. There are blends out there that work similar to R12 (Duracool etc) but they're just not the same.

A R134 conversion is more preferred unless you know someone who still has some R12 and is willing to sell you a couple of pounds of it for less that $500.

When I converted my 91 pickup truck to R134, I had the ports on the hoses changed instead of using the conversion fittings. I took the lines to an AC shop and they silver soldered the proper R134 ports on. Looked better and no chance of leaks. New accumulator and R134 oil in the compressor and it works fine. Helps to have an AC machine to evac and charge the system properly.

 

ding ding ding ding!!!!!!!!!!!!!!!!!!!! we have a winner where is the sticky for how to do that. I don't really care about ac but the wife does. so happy wife happy ____ and it would come in handy for the 100+ days