86 silverado air cond upgrade.

[Ziegelsteinfaust]

Originally Posted by Greasey Harley

I work for a refrigeration company. Our shop truck is a '79 C30 with a 454 and original AC still in place. I went through the system, replaced all the O-rings and both rubber hoses.
Pressure tested it over night, then pulled a vacuum on it with our big Appion vac pump. After it achieved a nice, deep vacuum (500 Microns), I installed the proper amount of R-12 back into the system.
That thing will FREEZE YOU OUT! Even when it's triple digit temps, it's always cool in The Dually. The point being, there is nothing wrong with the design of the factory AC, and parts are still available.

My opinion is worth exactly what you are paying me for it.
-Russ

I do commercial hvac. Blends like r134a can get funky when fractionation has happened sometimes. R12 is pure, and not subject to that issue. In my case it is r410a, and r12 instead.

Alot of mechanics dont vaccum, and noncondensibles stay in. Ruining the performance. My sister's husband was looking at me like I was a freak using nitrogen on a friends truck. The compressor was changed, but I spent time blowing R11 flush through it since it had several dye packets added in its life time.