refrigerant type JAGUAR XJ6 1994 2.G Workshop Manual

Engine (AJ16)
3.1.2 ENGlNE/ TRANSMlSSlON UN/& RENEW
SRO 12.41.02/20
The engine/transmission unit on the AJ 16 normally aspirated and supercharged engined vehicles are fitted ontothree
engine mounting/bracket assemblies. The two front engine mountings for the 3.2/4.0 liter normally aspirated and the
4.0 liter supercharged engined vehicles are identical. They are fitted to the front crossmember on either side of the
engine bay. Rubber to metal
engine/transmission rear mounts used for both engine types, are secured to a support
bracket which traverses the two body underframe longitudinal members. For access to remove the engine carry out the following procedures:
WARNING: WHEN WORKING WlTHlN THE ENGINE COMPARTMENT, KEEP CLEAR OF THE RADIATOR COOLING
FANS AS THEY COULD START WITHOUT WARNING EVEN IF THE ENGINE IS NOT RUNNING.
. Remove the hood, see SRO 76.16.01, section 13
. Remove the air cleaner assembly.
. Depressurize the fuel system, see SRO 19.50.02, section 5.1.
Disconnect the battery.
. In line with the relevant SRO's and sections, remove all appropriate obstructing parts, including their fixing and
. Disconnect all mechanical and isolate all electrical linkages leading to and from the engine.
. De-gas the airconditioning system, see section 14, Charge Recovery (System depressurization).
mounting
arrangements.
CAUTION : Do not vent refrigerant directly to the atmosphere and always use Jaguar approved recovery/recycle/re- charge equipment.
. Drain the engine oil, see 3.1.3 this section.
. Drain the coolant, see SRO 26.10.01, section 4.1.
WARNING: DO NOT REMOVE THE HEADER TANK PRESSURE CAP WHILE THE ENGINE IS HOT. IF THE CAP MUST
BE REMOVED, PROTECT THE HANDS AGAINST ESCAPING STEAM AND SLOWLY TURN THE CAP ANTI- CLOCKWISE UNTILTHE EXCESS PRESSURE CAN ESCAPE. LEAVETHE CAP IN THIS POSITION UNTIL ALL
STEAM AND PRESSURE HAS ESCAPED AND THEN REMOVE THE CAP COMPLETELY.
Before lifting the complete engine/transmission unit with an engine hoist from the engine bay, ensure that two engine
lifting brackets (tool 18G. 1465) are secured equally spaced to the inlet manifold studs. The engine lifting brackets
should be positioned towards the front and the rear of the assembly. Ensure the front of the vehicle is jacked
up secure- ly on stands when removing the assembly.
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Climate Control Systems
Description U-
HFC 134A - ICI Klea or
equivalent
Polyalkyleneglycol (PAG) Compressor lubricant
Refrigerant
111.
Notes
Recyclable. NOT
compatible
with CFC 12
Absorbs water readily. NOT
compatible with mineral based
oils
SERVICE MATERIALS
Standard for Recovery I Recycle 1 Recharge Equipment.
Recovery rate
Cleaning capability
Oil separator
.Moisture indicator
Vacuum pump
Filter Replaceable with moisture indicator
Charge Hoses
Feature Requirement
0,014 - 0,062 m3 / min. (1,36 kg in 20 minutes)
15 parts per million (ppm) moisture; 4000 ppm oil; 330 ppm non condensable gases
in air
With hermetic compressor and automatic oil return
Sight glass type, sensitive to 15 ppm minimum
2 stage 0,07 - 0,127 m3 I min.
Selectable charge weight and automatic delivery
Dedicated HFC 134A port connections.
Iv. SERVICE DATA
Application
Charae weight
Lubricant capacity
Compressor pressure relief valve
Drive belt 12 cylinder
Drive belt tension
All figures apply to a cold belt
Special note
Drive belt tension measuring point
Drive belt 6 cyclinder
Drive belt tension
All figures apply to a cold belt
Drive belt tension measuring point
Specification
160 - 200 ml
Opening point 34 Bar. Closing point 27,6 Bar.
Maximum leakage rate of 113 liters 1 minute @ 41 Bar
7 rib Poly
-vee; 1450 mm long
Burroughs method
- New belt 790 N; If tension falls
below 270 N reset at 630 N
Clavis method
- New belt 114 to 120 Hz; If tension falls
below 70 Hz reset at 87 to 93 Hz
For new belt; rotate engine 3 revolutions minimum and
retension
Mid-way between crankshaft and compressor pulley ~
4
rib Poly-vee X 1010 mm long
Burroughs method
- New belt 556 to 578 N; If tension
falls below 245 N reset at 378 to 400
N
Clavis method - New belt 167 to 173 Hz; If tension falls
below 85 Hz reset at 127 to 133 Hz
Mid
-way between crankshaft and compressor pulley on
the upper run
1 Charge pressure I Heating element to increase pressure
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Climate Control Systems
0 Because HFC 134A is fully recycleable it may be 'cleaned' by the recovery equipment and re-used following
removal from a system.
0 Leak tests should only be carried out with an electronic analyzer which is dedicated to HFC 134A. Never use a CFC 12 analyzer or naked flame type.
0 Do not attempt to 'guess' the amount of refrigerant in a system, always recover and recharge with the correct
charge weight. In this context do not depress the charge or discharge port valves to check for the presence of
refrigerant.
14.1.3 Handling Lubricating Oil
0 Avoid breathing lubricant mist, it may cause irritation to your respiratory system.
0 Always decant fresh oil from a sealed container and do not leave oil exposed to the atmosphere for any reason
other than to fill or empty a system. PAG oil is very hygroscopic (absorbs water) and will rapidly become con-
taminated by atmospheric moisture.
PAG oil is
NOTcompatible with previously used mineral based oils and must NEVER be mixed (Fig. 1). Do not
re
-use oil when it has been separated from refrigerant, following a recovery cycle. Dispose of used oil safely.
14.1.4 System Maintenance
0 When depressurizing a system do not vent
refrigerant directlyto atmosphere, always use Jaguar
approved recovery equipment.
0 Always decant compressor oil from a sealed con- tainer and do not leave oil exposed to the atmosphere
for any reason other than to fill or empty
a system.
PAG oil is very hygroscopic and will rapidly become
contaminated by atmospheric moisture.
0 Plug pipes and units immediately after disconnection
and only unplug immediately priorto connection. Do
not leave the system open to atmosphere.
0 It is not necessary to renew the receiver drier when- ever the system has been 'opened' as previously ad-
vised - see note this page. However,if a unit or part
of the system is left open for more than five minutes,
it may be advisable to renew the receiver drier. This
guidance is based on
U.K average humidity levels;
therefore, locations with lower humidity will be less
critical to moisturecontamination of the unit.
It must
be stressed that there is not
a 'safe' period for workto
be carried out in: ALWAYS plug pipes and units im-
mediately after disconnection and only remove plugs
immediately prior to connection.
J82-387
Fin. 1
U: The receiver / drier MUST be renewed if the compressor has failed or if it is suspected that debris may be in
the system.
0 If replacement parts are supplied without transit plugs and seals DO NOT use the parts. Return them to your
supplier.
0 Diagnostic equipment for pressure, mass and volume should be calibrated regularly and certified by a third
party organization.
0 Use extreme care when handling and securing aluminium fittings, always use a backing spanner and take
special care when handling the evaporator.
0 Use only the correct or recommended tools for the job and apply the manufacturer's torque specifications.
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14.8 REFRIGERATION CYCLE:
The Compressor draws low pressure, low temperature re- frigerant from the evaporator and by compression, raises re- frigerant temperature and pressure. High pressure, hot
vaporized refrigerant enters the Condenser where it is
cooled by the flow of ambient air.
A change of state occurs
as the refrigerant cools in the condenser and it becomes a
reduced temperature high pressure liquid.
From the condenser the
liquid passes into the Receiver / Drier which has three functions,
a) Storage vessel for varying system refrigerant demand.
b) Filter to remove system contaminants. c) Moisture removal via the dessicant.
With the passage through the
receiver/drier completed the,
still high pressure liquid refrigerant enters the Expansion
Valve where it is metered through a controlled orifice which
has the effect of reducing the pressure and temperature.
The refrigerant, now
in a cold atomized state, flows into the
evaporator and cools the air which is passing through the
matrix.
As heat is absorbed by the refrigerant
it once again changes
state, into a vapour, and returns to the compressor for the
cycle to be repeated (Fig.
1).
There is an automatic safety valve incorporated in the com- pressor which will operate should the system pressure be in
excess of 41 bar. The valve will reseat when the pressure
drops below 27,6 bar.
W Thedivisionof HIGHandLOWsideissimplythesys- tem pressure differential created by the compressor
discharge (pressure), suction (inlet) ports and the
relative inlet and outlet ports
ofthe expansion valve.
This differential is critical to system fault diagnosis
and efficiency checks.
Twelve Cylinder Vehicles only:
Dual pressure switch: This two-function pressure switch
cuts electrical power to the compressor clutch if the system
pressure is outside of the range
of 2 Bar (1st Function) to 30
Bar (2nd Function).
Six Cylinder Vehicles only:
There are two switches incorporated into the high side of the
system which have the following functions:
a) Trinary; This three function pressure switch, cuts electri
-
cal power to the compressor clutch should the system pres- sure not be in a range of 2 bar (1st function) to 30 bar (2nd
function). The switch also provides a ground signal to oper
- ate the appropriate relay (within the 'Stribel,' unit) to ener- gize both engine cooling fans when maximum A/ C cooling
is required. Operation pressure, 20 bar input (3rd function).
b) Pressure Switch Slow Cooling Fans; When the system
pressure is 12 bar, medium A/ C demand, the operation of
this switch connects both engine cooling fans in series to op- erate at half battery voltage and so, half fan speed. 1.
Compressor
2. Condenser
3. Receiver / Drier 4. Expansion Valve
5. Evaporator
6. Pressure switch - Dual type
on 12
cyl & Trinary on 6 cyl
Fig. 1
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0 14.9 GENERAL SYSTEM PROCEDURES
14.9.1 Leak Test
Faults associated with low refrigerant charge weight and low pressure may be caused by leakage. Leaks traced to
mechanical connections may be caused by torque relaxation or joint face contamination. Evidence of oil around such
areas is an indicator of leakage. When checking for non visible leaks use only
a dedicated HFC 134A electronic analyzer
and apply the probe all round the joint / connection.
Should a leak betraced to a joint,checkthatthefixing issecuredtothecorrecttightening torque before any other action
is taken.
Do not forget to check the compressor shaft seal and evaporator.
CAUTION : Never use a dedicated CFC 12 or naked flame type analyzer.
14.9.2 Charge Recovery (System depressurization)
The process of HFC 134A recovery will depend on the basic characteristics of your chosen recovery/ recycle I recharge
equipment, therefore, follow the manufacturer's instructions carefully.
Remember that compressor oil may be drawn
out of the system by this process, take note of the quantity recovered
so that it may be replaced.
CAUTION: Observe all relevant safety requirements.
Wear suitable eye and skin protection
Do not mix HFC 134A with CFC 12. Do not vent refrigerant directly to atmosphere and always use Jaguar approved recovery I recycle I re- charge equipment.
Take note of the amount of recovered refrigerant, it will indicate the state of the system. 0
14.9.3 Evacuating the System
This process, the removal of unwanted air and moisture, is critical to the correct operation of the air conditioning sys-
tem. The specific procedures will vary depending on the individual characteristics of your chosen recovery I recycle / recharge equipment and must be carried out exactly in accordance with the manufacturers instructions. However,
it is recommended that the initially only the HIGH side valve be opened at the start of the procedure. After a short time a small depression should be seen on the LOW side, at which point the LOW side valve may be opened and the evacu- ation process completed. If a vacuum is not registered on the LOW side it may indicate that the expansion valve is
jammed closed or that the system is blocked. This simple check may save time and effort when the system is re- charged.
Moisture can be highly destructive and may cause internal blockages due to freezing, but more importantly, water sus- pended in the PAG oil will damage the compressor. Once the system has been opened for repairs, or the refrigerant
charge recovered, all traces of moisture MUST be removed before recharging.
14.9.4
The amount of oil drawn out during a recovery procedure will be dependent on the state of the system and the rate
of recovery. The quantity will be approximately 30 to 40 ml; this may vary, and the figure is given only for guidance.
The oil separator vessel in the recovery equipment must be clean and empty
at the start of the process so that the quan- tity of oil which is drawn out may be accurately measured.
Oil may be added by three methods,
1 and 2 being direct into the system and 3 with the compressor off the vehicle;
1. Via the recovery I recycle 1 recharge station.
2. Proprietary oil injector.
Adding Lubricating Oil - Compressor Related
1ynfa: Equipment manufacturer's instructions must be adhered to when using direct oil introduction.
3. Directly into the original, or new unit, because of rectification work to the existing compressor, or the need to fit a new compressor.
Original
From an existing compressor, drain the oil into a measuring cylinder and record the amount. Flush the unit out
with fresh PAG oil and drain thoroughly, Replenish the compressor with the same amount of PAG oil that was
originally drained out and immediately plug all orifices ready for refitting to the vehicle.
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14.12 MANIFOLD GAUGESET
The manifold gauge set is a most important tool fortracing faults and system efficiency assessment. The relationship
to each other of HIGH and LOW pressures and their correlation to AMBIENT and EVAPORATOR temperatures must be
compared to determine system status (see Pressure /Temperature graphs in Sub
-Sections 14.14 & 14.15).
Because of the heavy reliance upon this piece of equipmentfor service diagnosis, ensure that the gauges are calibrated
regularly and the equipment is treated
with care.
3
1 Low side service hose - BLUE
5 High side hand valve - RED 2 Low side hand valve - BLUE 6 High side service hose - RED
3 Low pressure compound gauge - BLUE 7 System service hose - NEUTRAL
4 High pressure gauge - RED
COLOUR (commonly yellow)
Fig. 1 Manifold gauge set
Manifold.
The manifold is designed to control refrigerant flow. When connected into the system, pressure is registered on both
gauges at all times. During system tests both the high and low side hand valves should be closed (rotate clockwise
to seat the valves). The hand valves isolate the low and the high sides from the centre (service) hose.
0 Low side pressure Gauge.
This compound gauge, is designed to register positive and negative pressure and may be typically calibrated - Full
Scale Deflection, 0 to 10 bar (0 to 150 Ibf / in2) pressure in a clockwise direction; 0 to 1000 mbar (0 to 30 in Hg) FSD
negative pressure in a counter clockwise direction.
High Side Pressure Gauge.
This pressure gauge may betypicallycalibrated from 0 to30 bar (0 to 500 Ibf/in2) FSD in a clockwise direction. Depend-
ing on the manufacturer, this gauge may also be of the compound type.
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