R134a refrigerant is used on many modern production vehicles as a refrigerant for the air conditioning system. Freon is no longer used as a refrigerant today, so if your air conditioning in your Nissan Quest starts to lose its cooling effect, you’ll need to use the R134a. Vehicles manufactured after 1995 must use R134a and vehicles manufactured before 1995 must locate a mechanic that can recharge the system with R-12 refrigerant since it is no longer commercially available. If your Quest is a 1993 or 1994 model year, you cannot use the R134a refrigerant without taking it to a mechanic to have modifications made to your cooling system.
Connect the recharge hose that came with your kit to the R134a can of refrigerant. The end of the hose that connects to the can has a valve and a handle that controls the flow of refrigerant. Screw this end of the hose onto the top of the can.