By the amounts of F**ks i give
The schrader valve on the low pressure side of the system.
the low pressure valve is on the passenger side. follow low pressure line and you will see it
Refrigerant is added to a 1997 Pontiac Grand Am by removing the cover on the low pressure coolant line and attaching a can of refrigerant. The valve on the can is then opened and the system will automatically pull the refrigerant in.
That sounds like the expansion valve.
evaporator
In order to have a successful refrigerant recovery, one must ensure the manifold gauge is set, set the valve, monitor the pressure and gross weigh while filling, and shut off the valve once the ideal pressure and weight are reached.
Thermal Expansion Valve is a type of metering device which is one of the separation points between the high and low pressure sides of an air conditioning system (the other being the compressor). It depressurises the liquid refrigerant which passes through it, ensuring that low pressure liquid refrigerant is passed on to the evaporator.
king valve
You only add refrigerant thru the LOW pressure valve. First check the pressure with a pressure gauge (should read between 25-45 psi) If low then start engin and turn AC on high. Attach refrigerant canaster to the low pressure valve to release refrigernt into the system. Canaster turns very cold and condensation appers on it as it releases into you a/c. Recheck pressure to make sure that is is at the proper PSI. You will hear the compressor kick on and off and the gague will fluctuate between the proper range.
On top of the air conditioning accumulator (can), located on the passenger side of your engine not too far from the electric fan motor for your heater core/ air conditioning evaporator. It has a plastic dust cap covering the valve.
You cannot increase steam pressure through a valve without adding heat to it. Throttling steam always reduces its pressure.
1999 Buick Century low pressure A/C valve for adding R-134a refrigerant (freon). The low pressure A/C valve is located in about the upper center of the firewall to the right of the heater core inlet and outlet (right side - as if your sitting in the driver's seat). Look for a black plastic cap behind the transaxle (red-handled) dipstick.