Operation CHARM: Car repair manuals for everyone.

Air Conditioning System






Air conditioning system





AC installation in the car
The air conditioning used in this car is a conventional installation where a thermostat-controlled expansion valve (TEV/TXV) works as control valve.
The expansion valve controls the amount of refrigerant that passes the evaporator. The quantity depends on the temperature in the evaporator's outlet pipe. If the temperature is too low the amount is reduced slightly by closing the valve. When the temperature increases, the valve opens slightly again to let in more fluid in the evaporator. In this way, a balanced state is achieved.
The filler nipple is located against the engine compartment wall in the high-pressure line.
The AC-system is filled with environment-friendly R134a refrigerant, just like all other Volvo cars.
The system has two filler nipples. One in the high-pressure circuit for the evaporator, and one in the low-pressure after the evaporator.