1998 JAGUAR X308 clutch

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.

Probable
causes of faults may be found by comparing actual
system pressures, registered on your manifold gauge set or
recovery / recharge / recycle station, and the relevant pressure to temperature relationship graph. The following chart
shows the interpretation that ma y be made by this difference.
• NOTE: The A/CCM will disengage the compressor clutch should the evaporator temperature fall to 0°C.
• NOTE: Graphs are typical for HFC 134A
The 'Normal' condition is that which is relevant to the prevailing evaporator temperature.
System Pressure Fault Classification
• NOTE
: If erratic or unusual gauge move
ments occur, check the equipment against a known (calibrated) manifold gauge
set.
This table should be used in conjunction with the graphical representations of 'High side' pressure / ambient temperature
and 'Low side' pressure / evaporator temperature.
Leak
Test
F
a
ults associated with low re
frigerant charge weight and low pressure ma y be caused by leakage. Leaks traced to
mechanical connections may be caused by to rque relaxation or joint face contamination. Evidence of oil around such areas
is an indicator of leakage.
Models that have fluorescent tracer dye incorporated into the refrigeration system can be checke d for non-apparent leaks by
scanning with a high intensity ultraviolet lamp. The location of leaks can be pinpointed by the bright yellow glow of the
tracer dye.
CAUTION: Observe ALL safety precautions associated with ultraviolet equipment.
Should a leak be traced to a joint, check that the fixing is secured to the correct tightening torque before taking any other
action.
When examining the system for leaks, chec k the compressor shaft seal and evaporator.
Charge Re
covery (system depressurization)
The process of
charge r
ecovery will depe
nd on the basic characteristics of your chosen recovery / recycle / recharge
equipment, therefore, follow the manu facturer's instructions carefully.
Remember that compressor oil may be drawn out during this process, take note of the quantity recovered so that it may be
Lo
w side
gauge reading
High s i
de
gauge reading
Fau l
t
Cause
No
r
mal
No
r
mal
Di
sc
harge air initially cool then
warms up
Mois
ture in system
N
ormal
to low
No
r
mal
As aboveAs above
LowLowD
i
scharge air slightly cool
Ref
r
igerant charge low
LowLowDi

scharge air warm
Refr
igerant charge very low
LowLowDi

scharge air slightly cool or frost
build up at expansion valve
Expansion valve st
uck closed
LowLowDi

scharge air slightly cool,
sweating or frost after point of restriction
Restri
ction in High side of system
HighLowCompressor noisyDe
fe
ctive compressor reed valve
HighHighD
i
scharge air warm and high side
pipes hot
Refri
gerant charge high or inefficient condenser
cooling due to air flow blockage or engine cooling fans
not working
HighHighD i
scharge air warm / Sweating or
frost at evaporator
Expans ion valve st
uck open

Sym
ptom #2
Sy
mptom #2
Sym

ptom #3
Sy
mptom #3
No
cooling
Compressor sei
zed
Compressor seal failure
Compressor valve or piston damage
*
*
*
R
enew compressor
*
Compressor cl
utch / circuit faulty
*
R
efer to PDU
*
D
rive belt slack / broken
*
Adjust or r
enew
*
B
lower motor / circuit faulty
Pressure switch / circuit fault
*
*
R
efer to PDU
*
Total l
oss of refrigerant caused by broken pipe or joint
*
Repair / renew. Check code 2
3
*
P
artial loss of refrigerant caused by leaking joint or pipe
*
R
epair / renew, check fault code #23
*
Conden
ser damage
*
Re
new, check fault code #23
*
Bl
ocked receiver / drier filter
*
R
enew receiver / drier
*
Evaporator senso
r / circuit faulty
*
R
efer to PDU, check fault code #13
*
Bl
ocked pollen filter (if fitted)
*
Cle
an or renew
*
• NOTE: Should a leak or low refrigerant be established as the cause of INSUFFICIENT COOL ING, follow the procedures
Recovery / Recycle / Recharge, this section, and ob serve all refrigerant and oil handling instructions.
Sy
mptom
Possib
le Sources
Acti
on
Insuffi

cient
cooling
Compre
ssor clutch slipping
*
R
enew clutch assembly
*
Fl
aps or vents closed / seized
*
Check f
ault codes #41 to 46
*
Bl
ower circuit fault
*
R
efer to PDU
*
Bl
ocked condenser matrix / fins
*
Check hig
h / low side pr
essures / renew. Check /
clean fins
*
Bl
ocked evaporator matrix
*
Check hig
h / low side
pressures / renew
*
Bl
ocked pollen filter (if fitted)
*
Cle
an or renew
*
Evaporator temp
erat
ure sensor faulty
*
R
efer to PDU
*
P
artial loss of refrigerant caused by leaking joint

or pipe
*
R
epair / renew
*
Blocked expan
sion valve
*
Check hig
h / low side
pressures / renew
*
Expans
ion valve fault
*
Chec
k system pres
sure differential
*
C
ollapsed air conditioning hose hose
*
Check hig
h / low side
pressures / renew
*
Moi
sture or air in the system
*
Chec
k system pressures
*
Low r
efrigerant charge
*
Initiate recovery
procedure, check fault code #23
*
Coo
lant flow valve open
*
Chec
k operation
*
Sy
mptom
Possib
le Sources
Acti
on
Int

ermittent cooling
Compre
ssor clutch slipping
*
R
enew clutch assembly
*
Compressor cl
utch circuit faulty
Blower(s) circuit faulty
*
*
R
efer to PDU
*
Motorized in-car aspirator faulty

*
R
efer to PDU, check fault code #11
*
Evaporator temp
erature sensor faulty

*
R
efer to PDU, check fault code #13
*
Bl
ocked condenser matrix / fins
*
Check hig
h / low side pressures / renew. Check / clean fins

*
Bl
ocked evaporator matrix
*
Check hig
h / low side
pressures / renew
*


Sym
ptom #1
Sy
mptom #1
Sy

mptom
Possib
le Sources
Acti
on

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)

Air Conditioning - Air Conditioning (A/C) Compressor
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. Remove supercharger drive belt (where fitted); refer to
18.50.08.
4. Remove front end accessory dr ive belt; refer to 12.10.40 or
(SC) 12.10.40.

5. NOTE: A commercially availa ble brake pipe clamp is
recommended. Do not over tighten.
Clamp power steering reservoir to pump feed hose.
6. Raise vehicle for access

7. NOTE: Position drain tin to collect the fluid when union nut is
released.
Disconnect steering rack hose from pump. 1. Release union nut.
2. Discard O-ring.
3. Install suitable blanking plugs.

8. Disconnect clutch harness connector from compressor.
1. Disconnect connector.
9. Disconnect lines from compressor.
Discard O-rings.
Install suitable blanking plugs.

3. Install lines to compressor.
Install new O-ring seal and lubricate with clean
compressor oil.

4. Connect clutch harness connector to compressor.
1. Connect clutch connector.

5. Connect power steering hose to pump.
1. Remove blanking plugs.
2. Install new O-ring seal and lubricate with clean
compressor oil.
3. Tighten union nut.
6. Lower ramp.
7. Unclamp power steering rese rvoir to pump feed hose.

The solar sensor is mounted on the top surface of the fascia between the defrost outlets.
The sensor is a photo-diode which is calibr ated to measure direct sunlight. It provides an output signal to the A/CCM which
automatically reduces air temperature an d increases fan speed (airflow volume) to compensate for solar heating.
Evaporator Sensor

This thermistor device changes electrical resistance as a result of temperature variations.
The sensor is positioned next to the evaporator fins and measures air temper ature after it has passed through the
evaporator. The sensor inputs a signal to the A/CCM which controls the compress or (see table) when the refrigeration
system is operating.
The sensor's connector is located on the LH side of the air conditioning unit, in front of the main power connector.
The A/CCM disengages the compressor clutch when the temperature of the air off the evaporator is 2° C or less. This is to
prevent the moisture which may collect between the cooling fins of the evaporator from freezing and thus restricting airflow.

Heater Matrix Temperature Sensor
Evaporator Temperature SignalCompressor State
3°CON - clutch engaged
2°COFF - clutch disengaged