Rear
PLUMBING- REARSpring-lock refrigerant line couplers are used to connect many of the refrigerant lines and other components to the refrigerant system. These couplers require a special tool for disengaging the two coupler halves.
High pressures are produced in the refrigerant system when the air conditioning compressor is operating. Extreme care must be exercised to make sure that each of the refrigerant system connections is pressure-tight and leak free. It is a good practice to inspect all flexible hose and metal refrigerant lines at least once a year to make sure they are in good condition and properly routed.
The refrigerant lines and hoses are coupled with other components of the HVAC system with peanut- block style fittings. A stat-O seal type flat steel gasket with a captured compressible O-ring, is used to mate plumbing lines with A/C components to ensure the integrity of the refrigerant system.
The metal refrigerant lines are repairable using a A/C Tube Repair kit such as Kent Moore model J-41425 or equivalent.
REAR EVAPORATOR
The rear evaporator coil is located in the rear heater-A/C unit housing, in the right rear quarter panel. The evaporator coil is positioned in the heater-A/C unit housing so that all air that enters the housing must pass over the fins of the evaporator before it is distributed through the system outlets. However, air passing over the evaporator coil fins will only be conditioned when the compressor is engaged and circulating refrigerant through the evaporator coil tubes.
Refrigerant enters the evaporator from the rear expansion valve as a low-temperature, low pressure mixture of liquid and gas. As air flows over the fins of the evaporator, the humidity in the air condenses on the fins, and the heat from the air is absorbed by the refrigerant. Heat absorption causes the refrigerant to boil and vaporize. The refrigerant becomes a low-pressure gas when it leaves the evaporator. The rear evaporator coil cannot be repaired and, if faulty or damaged, the rear evaporator coil must be replaced.
REAR EXPANSION VALVE
Vehicles equipped with the optional rear A/C unit have an H-type thermal expansion valve (TXV) located on the rear HVAC unit, behind the passenger side rear quarter trim panel. It performs the same function as the front expansion valve, to monitor refrigerant temperature and pressure at the control head and meter the refrigerant entering the evaporator to meet the vehicle cooling requirements.
The rear expansion valve is a factory calibrated unit and cannot be adjusted or repaired. If faulty or damaged, the rear expansion valve unit must be replaced.
REAR HEATER CORE
The rear heater core is located in the heater-A/C housing in the right rear inside quarter panel. It is a heat exchanger made of rows of tubes and fins. The heater core is not repairable and if damaged it must be replaced.
Engine coolant is circulated through heater hoses/ tubes to the heater core at all times. As the coolant flows through the heater core, heat removed from the engine is transferred to the heater core fins and tubes. Air directed through the heater core picks up the heat from the heater core fins. The blend air door allows control of the heater output air temperature by controlling how much of the air flowing through the heater-A/C housing is directed through the heater core. The blower motor speed controls the volume of air flowing through the heater-A/C housing. The heater core cannot be repaired and, if faulty or damaged, it must be replaced. Refer to Cooling System for more information on the engine cooling system, the engine coolant and the heater hoses.
REAR UNDER BODY HEATER LINES
1/2" Front Heater Tube Repair
1. Pinch hoses in engine compartment using spring clamp pliers.
2. Remove air box.
3. Remove passenger front tire.
4. Remove front inner fender well.
5. Disconnect the heater hose from underbody heater line using constant tension clamp pliers.
6. Drain coolant from underbody heater lines into an approved container.
7. Remove line brackets as necessary.
8. Mark cut location on tube on vehicle.
9. Cut tube on vehicle.
10. Size replacement tube, same as tube removed from vehicle.
11. Scuff end of both tubes using pad provided in special tool kit.
12. Select proper Lokring for 1/2" tube.
13. Put a drop of sealer from kit in the end of each tube, install Lokring and rotate to spread sealer evenly.
14. Select the proper jaws for the installation tool 1/2" from the kit.
15. Put installation tool over the Lokring with tubes installed (tube must be bottomed out in Lokring).
16. Compress Lokring using a wrench to draw the screw tight on the installation tool. Tighten the tool until the Lokring is bottomed out.
17. Back off the screw and remove the installation tool.
18. Reconnect the heater hose to the heater line.
19. Fill the cooling system.
20. Reinstall the front inner fender well.
21. Reinstall the front passenger side tire.
22. Reinstall the air box.