LR3/Disco 3
to the evaporator. The restriction across the valve reduces the pressure and temperature of the refrigerant and changes it
to a fine spray, which improves the evaporation process. Valve opening is controlled by the pressure in a capillary tube
containing a temperature sensitive fluid. One end of the capillary tube is connected to a diaphragm housing on the
thermostatic expansion valve, the other end of the capillary tube is sealed and attached to the refrigerant outlet line of the
evaporator. As the temperature of the refrigerant leaving the evaporator changes, a corresponding change of capillary
tube pressure and valve opening are produced. The warmer the refrigerant leaving the evaporator becomes, the greater
the volume of refrigerant allowed through the valve.
Evaporator
The evaporator is installed in the auxiliary climate control assembly between the blower and the heater matrix, to absorb
heat from the recirculated air. Low pressure, low temperature refrigerant changes from liquid to vapor in the evaporator,
absorbing large quantities of heat as it changes state. Most of the moisture in the air passing through the evaporator
condenses into water, which drains out of the auxiliary climate control assembly through the evaporator drain tube.
HEATING CIRCUIT
Two heater lines, supply and return, connect the heater core in the auxiliary climate control assembly to the engine
cooling system. The heater lines are routed along the rear crossmember, around the right rear wheel arch and along the
RH underside of the vehicle. The heater lines are connected to the engine cooling system at the rear of the engine
compartment. The heater lines consist of sections of aluminum alloy pipes, insulated with foam rubber, which are
connected together with rubber hose joints. Quick release fittings connect the heater lines to the engine cooling system.
Heater Lines
