# How to recharge the ac on a 1986 720 Kingcab pick up.



## 1978elk (7 mo ago)

I'd like to learn how to recharge the ac on my 86 720 Nissan pickup. I plan to use the R134 freon in it. I would like to know where to attach freon tube and gauge on the system? I would also like to know and see the problem areas where it could have leaks? Thank you in advance for your ideas.


----------



## rogoman (Dec 16, 2004)

1978elk said:


> I'd like to learn how to recharge the ac on my 86 720 Nissan pickup. I plan to use the R134 freon in it. I would like to know where to attach freon tube and gauge on the system? I would also like to know and see the problem areas where it could have leaks? Thank you in advance for your ideas.


One important thing to consider during the conversion of R12 to R134a is the PAG oil (Polyalkylene Glycol, a lubricant) which comes standard in R134a cans. This oil is *not compatible with R12*. If the R12 isn’t 100% flushed out of the system during a conversion, the newly introduced PAG oil will eventually turn into a gelatin-like substance, foregoing its ability to lubricate (PAG oil does not tolerate chlorine, which is found in R12).

Possible problem areas are where O-rings are used. When car makers used R-12 as the refrigerant and mineral oil as the lubricant in auto AC systems, they often used neoprene AC O-rings and gaskets. Neoprene and Buna O-rings worked well in those R-12 applications. But as R-12 was phased out and R-134a took its place, they found the neoprene and Buna O-rings didn’t hold up as well. So they switched to HNBR green O-rings.

Instead of me trying to explain the conversion process of R12 to R134A, here are some video clips explaining the process:





how to convert an ac cooling system from freon to r134 at DuckDuckGo


DuckDuckGo. Privacy, Simplified.




duckduckgo.com










how to convert an ac cooling system from freon to r134 at DuckDuckGo


DuckDuckGo. Privacy, Simplified.




duckduckgo.com


----------

