Jeep Grand Cherokee WK. Manual - part 1782

CORE-VALVE-SERVICE PORT

DESCRIPTION

Refrigerant system service ports are used to recover,
recycle, evacuate , charge and test the A/C refrigerant
system. Unique sizes are used on the two service
ports for the R-134a refrigerant system to ensure the
system is not accidentally contaminated with R-12
refrigerant or by service equipment used for R-12
refrigerant.

NOTE: 4.7L engine shown in illustration. Service
ports for other engines are located in similar loca-
tions.

The high side service port (1) is located on the receiv-
er/drier (2) near the right side of the radiator (3) and
its protective cap is attached to the service port with a
tether strap. The low side service port (4) is located on
the A/C suction line (5) near the dash panel (6). Both
the high side and low side A/C service port valve
cores are serviceable.

NOTE: The protective cap aids in service port sealing and helps protects the refrigerant system from con-
tamination. Remember to always reinstall the protective cap onto the service port when refrigerant system
service is complete.

Each of the service ports has a threaded plastic protective cap installed over it from the factory. The service port
caps are serviceable items.

REMOVAL

WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.

NOTE: Typical A/C service port shown.

1. Remove the protective cap (1) from the service

port (2).

2. Recover the refrigerant from the refrigerant system

(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING

STANDARD

PROCEDURE

REFRIGERANT SYSTEM RECOVERY).

3. Using a Schrader-type valve core tool, remove the

valve core (3) from the service port.

4. Install a plug in or tape over the opened service

port(s).

24 - 476

PLUMBING

INSTALLATION

NOTE: Typical A/C service port shown.

1. Lubricate the valve core (3) with clean refrigerant

oil prior to installation. Use only refrigerant oil of
the type recommended for the A/C compressor in
the vehicle.

2. Remove the tape or plug from the service port (2).

CAUTION: A valve core that is not fully seated in
the A/C service port can result in damage to the
valve during refrigerant system evacuation and
charge. Such damage may result in a loss of sys-
tem refrigerant while uncoupling the charge adapt-
ers.

3. Using a Schrader-type valve core tool, install and

tighten the valve core into the service port(s).

4. Evacuate the refrigerant system (Refer to 24 -

HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).

5. Charge the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-

CEDURE - REFRIGERANT SYSTEM CHARGE).

NOTE: The protective cap helps aid in service port sealing and helps protects the refrigerant system from
contamination. Remember to always reinstall the protective cap onto the service port when refrigerant sys-
tem service is complete.

6. Install the protective cap (1) onto the service port.

EVAPORATOR-A/C

DESCRIPTION

The A/C evaporator (1) for the heating-A/C system is
located within the HVAC housing, behind the instru-
ment panel. The A/C evaporator and it’s insulator (2)
are positioned in the HVAC housing so that all air
entering the housing must pass over the evaporator
fins before it is distributed through the heating-A/C
system ducts and outlets. However, air passing over
the evaporator fins will only be conditioned when the
A/C compressor is engaged and circulating refrigerant
through the A/C evaporator.

The A/C evaporator tubes (3) are connected and
sealed to the A/C expansion valve by use of rubber
O-rings (4) and a tapping block (5).

The A/C evaporator can only be serviced by removing
and disassembling the HVAC housing assembly.

PLUMBING

24 - 477

OPERATION

Refrigerant enters the A/C evaporator from the A/C expansion valve as a low-temperature, low-pressure mixture of
liquid and gas. As air flows over the fins of the A/C 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 A/C evaporator.

The A/C evaporator cannot be repaired and, if faulty or damaged, it must be replaced.

REMOVAL

1. Remove the HVAC housing (Refer to 24 - HEAT-

ING

AIR

CONDITIONING/DISTRIBUTION/

HOUSING-HVAC - REMOVAL).

2. Disassemble the HVAC housing as necessary to

access the A/C evaporator (1) (Refer to 24 - HEAT-
ING

AIR

CONDITIONING/DISTRIBUTION/

HOUSING-HVAC - DISASSEMBLY).

3. Open the rubber seal (1) and carefully lift the A/C

evaporator (2) and insulator (3) out of the lower
half of the HVAC housing (4).

4. If required, remove the rubber seal from the lower

half of the HVAC housing. If the seal is deformed
or damaged, it must be replaced.

5. If required, remove the insulator from the A/C evap-

orator. If the insulator is deformed or damaged, it
must be replaced.

INSTALLATION

NOTE: If the front A/C evaporator is being replaced, add 60 milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the type recommended for the A/C compressor in the vehicle.

1. If removed, install the insulator (3) over the A/C

evaporator (2). If the seal is deformed or damaged,
it must be replaced.

2. If removed, install the rubber seal (1) into the lower

half of the HVAC housing (4). If the seal is
deformed or damaged, it must be replaced.

3. Install the A/C evaporator into the lower half of the

HVAC housing. Make sure that the evaporator
drain within the HVAC housing is clean and unre-
stricted and that the insulator and rubber seal are
properly installed.

4. Assemble the HVAC housing (Refer to 24 - HEAT-

ING

AIR

CONDITIONING/DISTRIBUTION/

HOUSING-HVAC - ASSEMBLY).

5. Install the HVAC housing (Refer to 24 - HEATING

& AIR CONDITIONING/DISTRIBUTION/HOUSING-
HVAC - INSTALLATION).

24 - 478

PLUMBING

LINE-A/C DISCHARGE

DESCRIPTION

NOTE: 4.7L engine shown in illustration. A/C discharge line for other engines are similar.

The A/C discharge line (1) is the refrigerant line that
carries refrigerant from the A/C compressor (2) to the
A/C condenser (3). The A/C discharge line on models
equipped with the 5.7L engine include a fitting for the
A/C pressure transducer. For more information refer to
24 - HEATING & AIR CONDITIONING/CONTROLS/
TRANSDUCER-A/C PRESSURE - DESCRIPTION.

CAUTION: Use only seals specified for the vehicle.
Failure to use the correct seals will cause the
refrigerant system connections to leak.

The A/C discharge line has no serviceable parts
except for the dual plane seals. The seals used on the
connections are made from a special type of rubber
not affected by R-134a refrigerant. The seals must be
replaced whenever the A/C discharge line is removed
and installed.

If the A/C discharge line is found to be leaking or is
damaged, it must be replaced.

REMOVAL

3.7L/4.7L ENGINES

1. Recover the refrigerant from the refrigerant system

(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING

STANDARD

PROCEDURE

REFRIGERANT SYSTEM RECOVERY).

2. Disconnect and isolate the negative battery cable.

3. Remove the grille (Refer to 23 - BODY/EXTERIOR/

GRILLE - REMOVAL).

4. Remove the air cleaner housing, air intake tube

and the resonator (Refer to 9 - ENGINE/AIR
INTAKE

SYSTEM/HOUSING-AIR

CLEANER

REMOVAL).

5. Remove the nut (1) that secures the A/C discharge

line (4) to the A/C compressor (2).

6. Disconnect the A/C discharge line from the A/C

compressor and remove and discard the dual plane
seal.

7. Remove the nut (5) that secures the A/C discharge

line to the A/C condenser (3).

PLUMBING

24 - 479

Content .. 1780 1781 1782 1783 ..