R134 refrigerant replaced the old R12 Freon as an environmentally friendly alternative for powering automotive air conditioning systems in the late 1990s. While replacing the R134 isn't a necessary operation, you may need to evacuate and recharge the AC system in order to perform a leak repair or replace a failed component. There are special service machines specifically designed to work with R134 air conditioning systems, which are not readily available to the general population. With that in mind, it's best to leave this repair to a certified professional.
Open the Buick's hood and locate the AC service port caps, one red and one blue (usually), located on the silver AC manifold lines and the silver receiver/dryer tank. Remove the caps by hand to expose the AC service ports.
Attach the color-coordinated AC service hoses from the AC service machine to the AC service ports. Tighten the service hoses onto the ports by hand.
Evacuate the Buick's AC system with the AC service machine following the machine's specific user guide. This procedure will vary according to the year, make and model of your AC machine, but it normally involves setting the switches or dials to the evacuation setting.
Vacuum test the Buick's AC system with the AC service machine following the machine's user guide to make sure there are no leaks.
Recharge the Buick's AC system with the AC service machine following the machine's specific user guide. Disconnect the AC service hoses. Reinstall the service port caps and close the hood.
