Suggestions needed: HOW TO FILL AC Guide

Hello everyone,

I own 1996 Riviera. CUrrently, its dual-zone climate control does not blow freezing air out of driver's side and rear. THe only side which has true AC is front pass.

I would like to pressure check AC system and possibly fill it up to try to fix the issue i am having.


Is there a website to explain how to refill AC in new AC systems. Dos and donts. Name of the instrument to fill it up with (which contains pressure guages and valves)



Thank you.

the charging aparatus with the gauges and valves is called a manifold. most of the time the refrigerant charge is given by weight so scales are involved and the system is charged after being evacuated (dead empty).

if your buick does have three evaporators then two failures out of three is suspicious and i'd reccomend diagnosing the air controls before you look at the ac system itself. if there is no problem with the air controls then it is possible that the oriface tubes before the failed evaporators are clogged, as a lack of refirgerant would cause all three registers to blow warm air (assuming there really are three evaporators).

if you have to open the system for maintenance:

do not vent refrigerant to the atmosphere, have it recovered at a shop
do not inhale refrigerant (especially R134a)
do not overcharge the system

do replace the desicant cartriage (trust me, all will be in vain if you don't)
do evacuate the system for as long as you can (see the first do, about two hours on the pump is sufficient, longer is better)
do replace all disturbed o-rings and seals with new parts
do use the correct oil charge
do flush the ac system if there is componet failure (probably better to give that job to a shop)

most of the tools required can be rented for the auto parts chain stores that rent tools, be prepared for a substantial deposit especially on the vaccume pump.