air filter LAND ROVER DEFENDER 1996 User Guide

12ENGINE
20
REPAIR OIL FILTER HEAD GASKET
Service repair no - 12.60.03
Remove
1.Clean filter head adaptor.
2.Disconnect oil cooler pipes and plug to prevent
ingress of dirt.
3.Disconnect oil pressure switch lead.
4.Remove 4 bolts and withdraw filter head,
complete with gasket.
5.Clean mating faces of filter head and cylinder
block.
6.Fit head with new gasket.
7.Tighten bolts to
45 Nm (33 lbf/ft).
8.Reconnect oil pressure switch lead.
9.Reconnect oil cooler pipes.CYLINDER HEAD GASKET
Service repair no - 12.29.02
Remove
1.Disconnect battery
2.Remove bonnet.
3.Drain coolant.
See COOLING SYSTEM,
Repair, Drain and refill cooling system
4.Remove air cleaner.See FUEL SYSTEM,
Repair, Air cleaner
5.Detach crankcase ventilation valve and side
breather hose from rocker cover and move to
one side.
6.Remove fuel injectors and pipes.
See FUEL
SYSTEM, Repair, Fuel injectors
7.Remove heater plugs.See FUEL SYSTEM,
Repair, Heater plugs
8.Disconnect radiator top hose from thermostat.
9.Disconnect bleed hose at thermostat.
10.Disconnect water pump hose at thermostat.
11.Disconnect water temperature sensor lead.

ENGINE
3
SPECIFICATIONS, TORQUENm
Turbo charger oil drain adaptor to block 42....................................................
Oil drain pipe to turbocharger 25....................................................................
Turbocharger oil drain pipe to adaptor 38.......................................................
Turbocharger oil feed pipe adaptor to block 25...............................................
Turbocharger oil feed pipe to adaptor 25........................................................
Oil feed pipe to turbocharger 19.....................................................................
Turbocharger to cylinder head (stud) 10.........................................................
Turbocharger to cylinder head (nut) 45...........................................................
Turbocharger to blanking plate 25..................................................................
Turbocharger to EGR valve 25.......................................................................
EGR delivery tube to valve 25........................................................................
EGR delivery tube to mixing tube 25..............................................................
Fuel lift pump to filter (union) 15.....................................................................
Fuel filter from lift pump (banjo bolt) 33...........................................................
Fuel filter to fuel injection pump (banjo bolt) 33..............................................
Fuel injection pump from fuel filter (banjo bolt) 25..........................................
Injector pipes to injectors and fuel injection pump 29.....................................
Spill rail to injectors (banjo bolt) 10.................................................................
Spill rail to injection pump (banjo bolt) 25.......................................................
Boost pipe injection pump (banjo bolt) 10.......................................................
Plug, rear of injection pump 29.......................................................................
PAS pump to mounting plate 25.....................................................................
PAS pump mounting plate to auxiliaries mounting bracket 25........................
PAS pump pulley to hub 25............................................................................
Starter motor (bolt and nut) 45........................................................................
Air conditioning compressor
Compressor mounting bracket to front cover 45.............................................
Compressor to mounting bracket (stud) 8......................................................
Compressor to mounting bracket (nut) 25......................................................
Belt tensioner pulley to tensioner arm 45........................................................
Belt tensioner assembly to front cover plate 25..............................................
Idler pulley to front cover plate 45...................................................................
Compressor belt guard (nut) 25......................................................................
Sensors to water outlet elbow (air/con) 25......................................................
Blanking plug, water outlet elbow (air/con) 25................................................
Generator
Generator mounting bracket to front cover 45................................................
Generator to mounting bracket 85..................................................................
Generator pulley to hub 95.............................................................................
Generator belt guard 25..................................................................................
Generator to auxiliaries mounting bracket 25.................................................
Tachometer electrical connection 4...............................................................

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION A mechanical lift pump, with a hand priming facility, is
driven by the camshaft, and is mounted on the RH
side of the engine.
A fuel filter, with a replaceable element and
incorporating a water separator, is mounted on the
front RH side of the engine compartment.
A fuel sedimentor may be fitted when the vehicle is
operating in more arduous conditions, and is used to
minimise water deposits in the fuel system before
reaching the fuel pump and filter.
Fuel injection is carried out by a Bosch direct injection
pump, incorporating a cold start advance unit and a
high idle setting. The pump is mounted on the RH side
of the engine and is driven directly by gears in the
front cover from the crankshaft. The pump meters and
distributes fuel to 4 pintle type injectors located in
pre-combustion chambers in the cylinder head. Four
heater plugs, located in the cylinder head directly
below each injector, are fitted to improve cold starting.
An optional hand throttle, for use with a centre power
take off, is located on the fascia to the LH side of the
fuse box, and is linked independently to the fuel
injection pump throttle lever.
Air intake
The air cleaner is mounted on the RH side of the
engine and is connected by hoses to the cold air
intake duct and turbocharger inlet. Fitted between the
air cleaner and turbocharger is the crankcase breather
hose which connects to a breather filter on the rocker
cover.
A single stage turbocharger, fitted between the
exhaust manifold and exhaust down pipe, is
connected by hoses to the air cleaner and an
intercooler which is mounted on the LH side of the
radiator. The intercooler is connected by a hose to the
inlet manifold. When an EGR valve is fitted to the
turbocharger, additional pipes/hoses are used to
connect the components.Exhaust gas recirculation (EGR), when fitted.
Exhaust gas recirculation is controlled by an ECU
mounted under the front centre seat or cubby box and
receives the following inputs:
·Engine temperature from coolant temperature
sender unit on LH side of cylinder head.
·Throttle position from potentiometer on injection
pump.
·Engine speed from speedometer.
When all correct signals are received, the EGR
solenoid allows vacuum to open EGR valve and
recirculate a portion of the exhaust gas. See J6196 for
the EGR system component location and 'Operation'
for full system function.

FUEL SYSTEM
7
DESCRIPTION AND OPERATION
FUEL SYSTEM COMPONENT LOCATION
1.Fuel filter bleed screw
2.Fuel filter
3.Turbocharger
4.Actuator
5.Air cleaner
6.Fuel injector7.Heater plug
8.Heater plug controller
9.Coolant temperature transmitter
10.Fuel injection pump
11.Fuel lift pump
12.Intercooler

FUEL SYSTEM
9
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the air and when fuel is
injected into the heated air, it ignites instantaneously.
During cold tarting, automatically controlled heater
plugs assist in raising the temperature of the
compressed air to ignition point.
A cold start advance unit advances the injection timing
to further assist starting. Idle quality is improved by
the high idle setting.
The engine is supplied with pre-compressed air by a
single stage turbocharger.
Exhaust gases passing over a turbine cause it to
rotate, driving a compressor mounted on the turbine
shaft. Air drawn from the cold air intake passes, via
the air cleaner, to the turbocharger where it is
compressed. Compression in the turbocharger warms
up the air considerably, so that it expands. As a result
the air mass per cylinder is reduced, having a
negative effect on power output. By fitting a charge-air
intercooler, located on the LH side of the radiator, the
air is cooled before reaching the cylinders. This
increases power output through increased mass of
oxygen in the combustion process, as well as
maximising engine durability, through maintaining
lower piston and head temperatures.
Fuel is drawn from the tank by a mechanical lift pump
and passes to the injection pump via a filter. In
addition to removing particle contamination from the
fuel, the filter incorporates a water separator, which
removes and stores water.
The sedimentor/s, when fitted, is located adjacent to
the fuel tank/s and separates contamination and water
particles in the fuel before reaching the fuel lift pump.
The injection pump meters a precisely timed, exact
quantity of fuel to the injectors in response to throttle
variations, injection timing varying with engine speed.
Any excess fuel delivered to the injection pump is
passed back to the tank via the spill return line.
Fuel is injected in a finely atomised form into the main
combustion chamber, the burning fuel expands
rapidly, creating extreme turbulence which mixes the
burning fuel thoroughly with the compressed air,
providing complete combustion.Cold Starting is assisted by heater plugs, a cold start
advance unit and a high idle setting.
Heater plugs
Heater plug operation is controlled by a timer unit,
start relay and resistor. When the ignition is turned on
the timer unit is energised, the heater plugs start to
operate and a warning light on the dashboard
illuminates, remaining on until the heater plugs are
automatically switched off.
The length of time the heater plugs will operate is
dependent on under bonnet temperature, which is
monitored by a sensor located in the timer unit.
Starting the engine results in the power supply to the
heater plugs passing through the resistor, which
reduces their operating temperature. The heater plugs
are cut out either by the temperature sensor in the
timer, or by a microswitch on the injection pump which
operates when the throttle is depressed.
Cold start advance
The cold start advance unit is connected to the engine
cooling system via hoses. It contains a temperature
sensitive element which is retracted when cold and
pulls the advance lever, via cable, towards the rear of
the pump against spring pressure. As coolant
temperature rises, the cold start element expands
releasing tension on the cable and allowing spring
pressure to move the advance lever forwards.
Exhaust gas recirculation (EGR), when fitted
Operation of the EGR system is dependent on the
following:
·Engine temperature - must be between 20°C and
100°C approx.
·Engine speed - must be between 630 and 2850
rev/min.
·Engine load - calculated by throttle position
sensor.
·EGR valve lift position.
·Duration of engine idling.

19FUEL SYSTEM
4
ADJUSTMENT TURBOCHARGER BOOST PRESSURE - CHECK
Service repair no - 19.42.06
1.Disconnect actuator hose from turbocharger and
insert a suitable 'T' piece connector.
2.Connect a short length of suitable hose to
turbocharger and 'T'piece.
3.Connect further hose to 'T' piece and pressure
gaugeLRT-12-011. The pressure gauge hose
must be long enough to reach into the vehicle
cab so that the gauge can be observed by driver
or passenger.
4.To check maximum boost pressure, drive
vehicle normally, but in such a manner that full
throttle can be maintained whilst climbing a hill
with engine speed held steady between 2,500
and 3,000 rev/min. Under these circumstances
boost pressure should read 0,95 - 1,09 Kgf/cm
2
(13.5 - 15.5 lb/in2).PRIMING THE FUEL SYSTEM
Service repair no - 19.50.01
NOTE: If the fuel system has been
completely drained carry out the
procedures for priming both the
sedimentor, if fitted, and fuel filter and injection
pump.
Sedimentor and fuel filter
If the sedimentor or fuel filter have been dismantled
and air has entered the fuel system carry out the
following procedure:
1.Slacken fuel filter bleed screw.
2.Operate hand priming lever on fuel lift pump until
fuel, free from air, emerges from filter.
NOTE: Ensure that the fuel pump lever is
on the bottom of operating cam when
priming, otherwise maximum movement of
the lever cannot be achieved.
3.Tighten filter bleed screw whilst fuel is still
emerging.

FUEL SYSTEM
5
REPAIR FUEL FILTER ASSEMBLY
Service repair no - 19.25.02
Remove
1.Disconnect battery.
2.Place a suitable container under filter element
and slacken filter bleed screw.
3.Slacken drain tap and allow fuel to drain from
filter element.
4.Slacken fuel inlet and outlet banjo connections.
5.Remove 2 bolts and nuts securing filter head to
inner wing.
6.Remove fuel inlet and outlet banjo bolts and
detach fuel pipes.
7.Remove filter assembly from vehicle. Unscrew
filter element, if necessary.
8.Plug fuel pipe ends to prevent ingress of dirt.Refit
9.Position filter assembly and fit fuel inlet and
outlet pipes using new copper sealing washers
both sides of the banjo connections.
10.Secure filter head to inner wing.
11.Fully tighten banjo connections.
12.Prime fuel system to remove any air trapped in
filter
See Adjustment, Priming the fuel
system
13.Reconnect battery.
FUEL FILTER ELEMENT
Service repair no - 19.25.07
For remove and refit procedure.
See Fuel filter
element

COOLING SYSTEM
1
DESCRIPTION AND OPERATION ENGINE COOLING SYSTEM
Description
The complete cooling system of the 300Tdi engine
incorporates three independent functions:- Engine
(coolant) cooling; Turbo (charge air) intercooling;
Engine oil cooling.The intercooler is a separate aluminium unit, located
on the LH side of the engine compartment adjacent to
the radiator, sharing the same upper and lower
mountings. For details of turbo intercooling
See
FUEL SYSTEM, Description and operation,
Operation
. The oil cooler matrix is an integral part of
the radiator. Pre-formed pipes/hoses are used to link
the components within the separate systems as
shown below.
Engine cooling system
1.Radiator
2.Thermostat housing
3.Radiator bottom hose
4.Viscous fan
5.Water pump
6.Radiator top hose
7.Heater return hose
8.Coolant supply hose
9.By-pass hose
10.Radiator bleed (purge) hose
11.Bleed (purge) hose, thermostat housing
12.'Y' piece ejector
13.Expansion tank14.Heater rail
15.Heater unit
16.Heater feed hose
17.Intercooler
18.Air cleaner
19.Air feed hose
20.Turbocharger
21.Charge air supply pipe/hose
22.Cooled charge air supply hose
23.Exhaust manifold
24.Engine oil cooler
25.Feed pipe, engine oil cooler
26.Return pipe, engine oil cooler
27.Oil filter

82AIR CONDITIONING
2
DESCRIPTION AND OPERATION Operation
Evaporator unit and expansion valve
High pressure liquid refrigerant is delivered to the
expansion valve which is the controlling device for the
air conditioning system. A severe pressure drop
occurs across the valve and as the refrigerant flows
through the evaporator it picks up heat from the
ambient air, boils and vaporizes. As this change of
state occurs, a large amount of latent heat is
absorbed. The evaporator is therefore cooled and as
a result heat is extracted from the air flowing across
the evaporator. The refrigerant leaves the evaporator,
on its way to the compressor, as a low pressure gas.
An evaporator sensor measures the air temperature at
the evaporator and engages or disengages the
compressor clutch to prevent icing of the air ways.
Compressor
The compressor, a pump specially designed to raise
the pressure of the refrigerant, is mounted on the front
of the engine and is driven by an independent drive
belt from the crankshaft pulley. The compressor draws
vaporized refrigerant from the evaporator. It is
compressed with a resulting rise in temperature and
passed on to the condenser as a hot, high pressure
vapour.
Condenser
The condenser is mounted directly in front of the
radiator and consists of a refrigerant coil mounted in a
series of thin cooling fins to provide the maximum
heat transfer. Air flow across the condenser is induced
by vehicle movement and assisted by two electric fans
attached to the frame of the condenser. The
refrigerant high pressure vapour enters the condenser
inlet on the RH side. As the vapour passes through
the condenser coils the air flow, assisted by the two
fans, carries the latent heat away from the condenser.
This induces a change of state resulting in the
refrigerant condensing into a high pressure warm
liquid. From the condenser, the refrigerant continues
to the receiver/ drier.
Receiver/drier
This component acts as a reservoir and is used to
hold extra refrigerant until it is needed by the
evaporator. The drier within the receiver unit contains
a filter and dessicant (drying material) which absorb
moisture and prevent dessicant dust from being
carried with the refrigerant into the system.AIR CONDITIONING AND HEATER CONTROLS -
LH DRIVE
1. Temperature control
Move the lever upwards (RED) to increase air
temperature, or downwards (BLUE) to reduce air
temperature.
2. Air conditioning switch
Press the switch (indicator lamp illuminates) to
activate the air conditioning. Press again to switch off.
3. Air recirculation control
Move the lever fully upwards to activate air
recirculation. Move the lever fully downwards to
cancel recirculation.
NOTE: Prolonged recirculation may cause
the windows to mist up.
4. Air distribution control
Lever fully up - air to windscreen vents (also provides
some air to the footwell).
Lever midway - air to fascia vents (also provides some
air to the footwell).
Lever fully down - air to footwell vents (also provides
some air to the windscreen).

AIR CONDITIONING
3
ADJUSTMENT REFRIGERANT RECOVERY, RECYCLING,
RECHARGING
WARNING: The air conditioning system is
charged with a high pressure, potentially
toxic refrigerant. Repairs or servicing must
only be carried out by an operator familiar with
both the vehicle system and the charging and
testing equipment.
All operations must be carried out in a
well-ventilated area away from open flame and
heat sources.
Always wear safety goggles and gloves when
opening refrigerant connections.
WARNING: Wear eye and hand safety
protection. Open connections slowly in
case liquid or pressure is present. Allow to
bleed off slowly.
CAUTION: Overcharging air conditioning
system will cause excessive head
pressure.
An air conditioning portable Refrigerant Recovery
Recycling Recharging Station for use with R134a
refrigerant incorporates all the features necessary to
recover refrigerant R134a from the air conditioning
system, to filter and remove moisture, to evacuate and
recharge with the reclaimed refrigerant. The unit can
also be used for performance testing and air
conditioning system analysis.
The operator must adhere to the equipment
manufacturers' instructions.
Recovery and recycling
1.Connect a Refrigerant Station to the high and
low pressure servicing connections.
2.Operate the refrigerant recovery system
according to the manufacturers instructions.
3.Measure the amount of oil discharged from the
system. Add an equal amount of new refrigerant
oil to compressor before evacuation sequence.
WARNING: Refrigerant must always be
recycled before reuse, to ensure that the
purity of the refrigerant is high enough for
safe use in the air conditioning system. Recycling
should always be carried out with equipment
which is design certified by Underwriter
Laboratory Inc. for compliance with SAE-J1991.
Other equipment may not recycle refrigerant to
the required level of purity.
A R134a Refrigerant Recovery Recycling
Recharging Station must not be used with any
other type of refrigerant.
Refrigerant R134a from domestic and commercial
sources must not be used in motor vehicle air
conditioning systems.
Evacuation and recharging
1.Add refrigerant oil to compressor if necessary.
2.Renew the receiver/drier.
CAUTION: When a major repair has been
carried out, a leak test should be carried
out using inert gas.
3.Connect a Refrigerant Station to the high and
low pressure servicing connections.
CAUTION: Whenever the refrigerant
system is opened, the receiver/drier must
be renewed immediately before evacuating
and recharging the system.
4.Operate the refrigerant evacuation system
according to the manufactures instructions.
NOTE: If the vacuum reading is below
700mmHg after 15 minutes, suspect a leak
in the system. Partially recharge the
system and check for leaks using an electronic
leak tester. Check suction lines first, then run the
compressor for 5 minutes and then check the high
pressure lines.
CAUTION: The system must be Evacuated
immediately before recharging
commences. Delay between Evacuation
and Recharging is not permitted.