1998 JAGUAR X308 Radiator

Transmission/Transaxle Cooling - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26 -
Transmission Cooling
Description and Operation
The transmission fluid cooling system maintains fluid temperature within specified limits.

Parts List
Component Descriptions
The transmission fluid pipes:
Transfer fluid from the transmission to the cooler under the action of the hydraulic system pump. Return the cooled fluid from th e cooler to the transmission.
The transmission fluid cooler:
Is a plate type made from aluminum. Is mounted in the engi ne cooling radiator right-hand end tank.
Overheating Protection
If the engine coolant or transm ission fluid temperatures exceed their predefined limits, th e transmission control module locks
the torque converter clutch. By reducing slip, this minimises th e amount of heat transferred to the engine cooling system from
the transmission fluid.

ItemPart NumberDescription
1—Fluid pipe, oil FROM cooler
2—Fluid pipe, oil TO cooler

Transmission/Transaxle Cooling - 4.0L SC V8 - AJ26 - Transmission
Cooling
Description and Operation
The transmission fluid cooling system maintains the fluid temperature within specified limits. The cooling element is located
in the engine cooling radiator LH end tank.
Fluid is circulated, under pressure, by the transmission pump to the cooler.
General Layout

Overheating Protection
If the engine coolant or transmission fluid temperatures exceed their predefined limits, the transmission control module
locks the torque converter clutch . By reducing slip, this minimises the amount of heat transferred to the engine cooling
system from the transmission fluid.

Heating and Ventilation - Heater Core
Removal and Installation
Removal
Installation

1.
Drain radiator coolant only; re fer to 26.10.01 or (SC) 26.10.01.
2. Remove instrument panel for access; refer to 76.46.01.

3. Remove driver footwell duct.
Remove screw.
Remove duct.

4. Disconnect cool air bypass serv o motor connector and heater
matrix pipes.
1. Disconnect connector.
• NOTE: Position suitable clot h to absorb coolant leakage
before disconnecting pipes.
2. Remove screws and retaining brackets.
3. Remove screws and matrix clamps.
• NOTE: Discard O-ring seals from pipes; fit suitable
blanking plugs.
Detach pipes from matrix.

5. Remove heater matrix from heater/cooler assembly.
1. Remove screw.
2. Remove retaining plate.
Reposition instrument panel support bracket to permit
removal of heater matrix (RHD only).
3. Remove heater matrix.
1. NOTE: Lubricate and install new O-ring seals.
Installation is the reverse of removal procedure.

Heating and Ventilation - Heater Core and Evaporator Core Housing
Removal and Installation
Removal
1. Disconnect battery ground cable (IMPORTANT, see SRO
86.15.19 for further information).
2. Recover refrigerant from air co nditioning system; refer to
82.30.30.
3. Drain radiator coolant only; refer to 26.10.01 or (SC)
26.10.01.
4. Remove instrument panel for access, refer to 76.46.01.

5. From under the hood: Disconnect air conditioning pipes at the
evaporator.
1. Remove bolts.
2. Discard O-rings.
3. Install suitable blanking plugs.

6. Disconnect heater hoses from heater matrix pipes.
1. Release spring band clips and disconnect heater hoses.
2. Install suitable blanking plugs.

7. From inside the vehicle: re move driver footwell duct.
Remove screw.
Remove duct.
8. Remove upper steering column lower fixings.
1. Remove nut.
2. Remove bolt.

Compressor:
Features
Engine mounted, driven by the accessory drive belt. Fixed displacement type. High-pressure relief valve, to avoid system over-pressure. ECM controlled clutch energized via a relay.
Receiver drier:
Vertically mounted on the ri ght-hand side of the engine compartment next to the engine coolant radiator. Fitted with the high-side charge port. Includes a fluorescent tracer dye me chanism to aid leak detection.
ItemPart NumberDescription
1—Compressor assembly
2—Condenser
3—Evaporator and heater matrix (internal)
4—Receiver drier
5—4-level pressure switch
6—Expansion valve (internal)
7—High-side charge port
8—Low-side charge port
9—Suction muffler
10—Discharge hose
11—Discharge pipe
12—Suction hose
13—Suction pipe
14—Liquid line
15—Jumper hose (condenser hose)

Condenser:
Multi-pass fin-over-tube type, mounted in front of the engine cooling pack and directly to the radiator.
Pressure (Bitron) switch:
Located in the discharge pipe. Provides a signal, via the A/CCM, to th e ECM, to disengage the compressor clut ch should the refrigerant pressure be
< 2 bar or > 30 bar.
Provides a hard-wired signal to the ECM, to switch the cool ing fans to HIGH speed at 22 bar rising pressure and to
LOW speed at 17,5 bar falling pressure.
Provides a hard-wired signal to the ECM, to switch the radiator cooling fans to LOW speed at 12 bar rising pressure
and to switch the fans OFF at 8 bar falling pressure.
Expansion Valve

Parts List
The expansion valve is located inside the heater / air conditioning unit and comprises of a diaphragm, connected by a
capillary tube to a temperat ure sensing bulb, which regulates the valve according to temperature variations at the
evaporator outlet pipe. This component is NOT serviceable. See 'Refrigeration Cycle'
Air Conditioning (Heater / Cooler) Unit
ItemPart NumberDescription
1—Valve body
2—Pressure spring
3—Diaphragm
4—Capillary tube
5—Temperature sensing bulb
6—Valve inlet
7—Valve outlet
8—Equalizer pipe

Air Conditioning - Condenser Core
Removal and Installation
Removal
1. Disconnect battery ground cable (IMPORTANT, see SRO
86.15.19 for further information).
2. Drain radiator coolant only; refer to 26.10.01 or (SC)
26.10.01.
3. Recover refrigerant from air co nditioning system; refer to
82.30.30.
4. Release both gas struts, set the engine cover fully forward to
the service access position an d support with a wooden (or
similar) strut.
5. CAUTION: Take care not to damage hood or radiator
grille.
Remove twin fan and motor as sembly; refer to 26.25.12.

6. Disconnect radiator bleed hose.
Release connection.
7. Remove retaining clip which secures transmission oil cooler
upper and lower pipes.

8. Disconnect transmission oil cooler lower pipe from radiator.
1. Release union nut and disconne ct pipe.
Discard O-ring seal.
2. Install suitable blanking plugs.
9. From above the vehicle, discon nect transmission oil cooler
upper pipe from radiator.
1. Release union nut and disconne ct pipe.
Discard O-ring seal.
2. Install suitable blanking plugs.

10. Disconnect radiator bottom hose.
1. Release hose retaining clip.
2. Disconnect hose.

11. Disconnect radiator top hose.
1. Release hose retaining clip.
2. Disconnect hose.

12. Disconnect connector from pressure switch.
13. Release radiator top retaining panel.
Remove bolts.