2002 LAND ROVER DISCOVERY water pump

FUEL DELIVERY SYSTEM - TD5
DESCRIPTION AND OPERATION 19-1-3
Description
General
The fuel delivery system comprises a fuel tank, fuel pump, fuel pressure regulator, five injectors and a fuel filter. The
system is controlled by the Engine Control Module (ECM) which energises the fuel pump relay and controls the
operation and timing of each injector solenoid.
Unlike other Diesel engines, the Td5 engine has no injection pump. The diesel direct injection system receives fuel
at pressure from a two stage fuel pump located in the fuel tank. The system incorporates a fuel return to the fuel pump,
via a fuel cooler attached to the inlet manifold and a fuel filter. A fuel pressure regulator is located in a housing on the
rear of the cylinder head. The regulator maintains the fuel delivered to the injectors at a constant pressure and returns
excess fuel back to the fuel filter and pump via the fuel cooler.
A fuel filter is positioned on the chassis to the right of the fuel tank. The fuel feed and return to and from the engine
passes through the filter. The filter also incorporates a water sensor which illuminates a warning lamp in the
instrument pack.
A moulded fuel tank is located at the rear underside of the vehicle between the chassis longitudinals. The tank
provides the attachment for the fuel pump and fuel gauge sender unit which is located inside the tank.
Fuel tank and breather
The fuel tank and breather system is a major part of the fuel delivery system. The fuel tank and breathers are located
at the rear of the vehicle between the chassis longitudinals.
Fuel tank
The moulded fuel tank is made from High Molecular Weight (HMW) High Density Polyethylene (HDPE). The diesel
tank is manufactured using a proportion of recycled plastic.
The tank is retained in position by a metal cradle which is secured to the chassis with two nut plates and bolts at the
rear and a stud plate and two nuts at the front. A strap above the tank is bolted to the chassis and restrains the tank
from moving upwards. The fuel tank has useable capacity of approximately 95 litres (25 US Gallons).
An aperture in the top surface of the tank allows for the fitment of the fuel pump and fuel gauge sender unit which is
retained with a locking ring.
A reflective metallic covering is attached to the tank with two scrivets to shield the tank from heat generated by the
exhaust system.
The fuel filler is located in the right hand rear quarter panel, behind an access flap. The flap is opened electrically
using a switch on the fascia which operates a release solenoid.
The filler is closed by a threaded plastic cap which screws into the filler neck. The cap has a ratchet mechanism to
prevent overtightening and seals against the filler neck to prevent the escape of fuel vapour. The filler cap has a valve
which relieves fuel pressure to atmosphere at approximately 0.12 to 0.13 bar (1.8 to 2.0 lbf.in
2) and opens in the
opposite direction at approximately 0.04 bar (0.7 lbf.in2) vacuum.
A moulded filler tube, made from HMW HDPE, connects the filler to the tank via a flexible hose. The filler tube is
connected at its top end behind the filler flap.

FUEL DELIVERY SYSTEM - TD5
DESCRIPTION AND OPERATION 19-1-9
Fuel filter
1Filter body
2Nut 2 off
3Bolt 2 off
4Rubber washer
5Water sensor6Filter element
7Air bleed valve
8Air bleed connection
9Copper washer 4 off
10Connector 3 off
The fuel filter is located at the rear of the vehicle, to the right of the fuel tank and is attached by a bracket with two
bolts and nuts to the right hand chassis longitudinal.
The filter has four quick release coupling connections; low pressure feed from the fuel pump, low pressure return to
the fuel pump, return line from the fuel pressure regulator and a bleed line to the fuel pump. The fuel filter removes
particulate matter from the fuel and also separates water which accumulates at the bottom of the filter.
An air bleed valve is located in the bleed line connection. The valve comprises a restrictor and a membrane. The
restrictor has a small hole in its centre. This allows air and fuel to pass through the membrane. Air can pass through
the membrane, but once the membrane is wet with fuel it will not allow further fuel to pass through.
The fuel filter has a replaceable screw-on canister type filter element which is sealed to the filter body with rubber
seals. The lower part of the canister has a screw connection for a water sensor. The filter has a flow rate of 180 litres/
hour (47.6 US Gallons/hour).

FUEL DELIVERY SYSTEM - TD5
19-1-10 DESCRIPTION AND OPERATION
Water sensor
The water sensor has a three pin electrical connector. When the sensor detects water in the filter it illuminates a
warning lamp in the instrument pack .

+ INSTRUMENTS, DESCRIPTION AND OPERATION, Description.
The water sensor attachment thread has a slot machined down one side. The filter can be purged of water by partially
unscrewing the sensor which aligns the slot in the threads with a corresponding hole in the sensor. When aligned,
water and fuel can flow down the slot and flows from a small cast tube on the side of the sensor. Re-tightening the
sensor misaligns the slot and stops the flow of fuel.
The water sensor receives a battery supply from the fuel pump relay in the engine compartment fusebox on one of
the electrical connector pins. The two remaining pins are connected to the instrument pack and an earth header joint.
The sensor operation uses the measurement of resistance between two electrodes submerged in the fuel and
activated by the presence of water.
When the ignition is moved to position II the warning lamp will illuminate for approximately two seconds to check
warning lamp functionality. TestBook can also illuminate the warning lamp to check its functionality.
When the filter is full with fuel and no water is present the resistance of the Diesel fuel will show a reading of 15 mA
maximum on the feed wire to the instrument pack. This current will not illuminate the water sensor warning lamp in
the instrument pack. When sufficient water surrounds both electrodes the resistance of the water will show a reading
of 130 mA maximum. This will supply sufficient voltage to the instrument pack to illuminate the warning lamp to alert
the driver to the presence of water in the fuel system.

COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-5
Description
General
The cooling system used on the Diesel engine is a pressure relief by-pass type system which allows coolant to
circulate around the engine block and heater circuit when the thermostat is closed. With coolant not passing through
the by-pass or the radiator promotes faster heater warm-up which in turn improves passenger comfort.
A coolant pump is mounted on a casting behind the PAS pump and is driven from the PAS pump at crankshaft speed
by the auxiliary drive belt. The pump mounting casting connects with passages in the cylinder block and pumps
coolant from the radiator through the cylinder block.
A viscous fan is attached to an idler pulley at the front of the engine. The fan is attached to a threaded spigot on the
pulley with a left hand threaded nut. The fan draws air through the radiator to assist in cooling when the vehicle is
stationary. The fan rotational speed is controlled relative to the running temperature of the engine by a thermostatic
valve regulated by a bi-metallic coil.
The cooling system uses a 50/50 mix of anti-freeze and water.
A Fuel Burning Heater (FBH) is available as an optional item for Diesel engine variants. The FBH is located on the
bulkhead and is connected in series in the coolant supply to the heater. The FBH is used to compensate for the
relatively low coolant temperatures inherent in the Diesel engine.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.
Thermostat housing
A plastic thermostat housing is located behind the radiator. The housing has three connections which locate the
radiator bottom hose, top hose and coolant pump feed pipe. The housing contains a wax element thermostat and a
spring loaded by-pass flow valve.
Thermostat - Main valve
The thermostat is used to maintain the coolant at the optimum temperature for efficient combustion and to aid engine
warm-up. The thermostat is closed at temperatures below approximately 82
°C (179°F). When the coolant
temperature reaches approximately 82
°C the thermostat starts to open and is fully open at approximately 96°C
(204
°F). In this condition the full flow of coolant is directed through the radiator.
The thermostat is exposed to 90% hot coolant from the engine on one side and 10% cold coolant returning from the
radiator bottom hose on the other side.
Hot coolant from the engine passes from the by-pass pipe through four sensing holes in the flow valve into a tube
surrounding 90% of the thermostat sensitive area. Cold coolant returning from the radiator, cooled by the ambient air,
conducts through 10% of the thermostat sensitive area.
In cold ambient temperatures, the engine temperature is raised approximately 10
°C (50°F) to compensate for the heat
loss of 10% exposure to the cold coolant returning from the radiator bottom hose.
By-pass flow valve
The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm-up. When the main valve
is closed and the engine speed is below 1500 rev/min, the coolant pump does not produce sufficient flow and pressure
to open the valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the
coolant through the heater matrix only. This provides a higher flow of warm coolant through the heater matrix to
improve passenger comfort in cold conditions.
When the engine speed increases above 1500 rev/min the coolant pump produces a greater flow and pressure than
the heater circuit can take. The pressure acts on the flow valve and overcomes the valve spring pressure, opening
the valve and limiting the pressure in the heater circuit. The valve modulates to provide maximum coolant flow through
the heater matrix and yet allowing excess coolant to flow into the by-pass circuit to provide the engines cooling needs
at higher engine rev/min.

COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-7
Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct the coolant into and out of the
engine, radiator and heater matrix. Plastic pipes are used for the bleed and overflow pipes to the expansion tank.
A bleed screw is installed in the radiator top hose and is used to bleed air during system filling. A drain plug to drain
the heater and cylinder block circuit of coolant is located on the underside of the coolant pump feed pipe.
Oil cooler
The oil cooler is located on the left hand side of the engine block behind the oil centrifuge and oil filter. Oil from the oil
pump is passed through a heat exchanger which is surrounded by coolant in a housing on the side of the engine.
Full water pump flow is directed along the cooler housing which also distributes the flow evenly along the block into
three core holes for cylinder cooling. This cools the engine oil before it is passed into the engine. A small percentage
of the coolant from the oil cooler passes into a metal pipe behind the engine. It then flows into the lower radiator via
a hose.
Fuel cooler
The fuel cooler is located on the right hand side of the engine and is attached to the inlet manifold. The cooler is
cylindrical in design and has a coolant feed connection at its forward end. A 'T' connection at the rear of the cooler
provides a connection for the coolant return from the heater matrix and coolant return from the fuel cooler.
The 'T' connection houses a thermostat which opens at approximately 82
°C. This prevents the cooler operating in
cold climates.
Two quick release couplings on the cooler allow for the connection of the fuel feed from the pressure regulator and
return to the fuel tank. A counter flow system is used within the cooler.
Fuel flows around a coolant jacket within the cooler and flows from the back to the front of the cooler. As the hot fuel
cools travelling slowly forwards it meets progressively colder coolant travelling in the opposite direction maintaining a
differential cooling effect.
EGR Cooler
The EGR Cooler is mounted on the front of the cylinder head. Coolant from the oil cooler flows around the EGR cooler,
cooling the exhaust gas, to improve exhaust emissions, before being returned to the expansion tank.
Coolant pump
1Drive lugs (hidden)
2Housing
3'O' rings4Cover
5Feed hose connection
6Impeller

COOLING SYSTEM - TD5
ADJUSTMENTS 26-1-13
ADJUST ME NTS
Drain and refill
$% 26.10.01
WARNING: Since injury such as scalding could
be caused by escaping steam or coolant, do not
remove the filler cap from the coolant expansion
tank while the system is hot.
Drain
1.Visually check engine and cooling system for
signs of coolant leaks.
2.Examine hoses for signs of cracking, distortion
and security of connections.
3.Position drain tray to collect coolant.
4.Remove expansion tank filler cap.
5.Remove drain plug access cover from
underbelly panel.
6.Remove drain plug from coolant pump feed
pipe and allow cooling system to drain. Discard
drain plug sealing washer.
Refill
1.Flush system with water under low pressure.
Do not use water under high pressure as it
could damage the radiator.
2.Fit new sealing washer to drain plug. Fit and
tighten drain plug in coolant pump feed pipe.
3.Fit access cover to underbelly panel.
4.Prepare coolant to required concentration.

+ CAPACITIES, FLUIDS AND
LUBRICANTS, Anti-Freeze Concentration.5.Remove bleed screw from top hose.
6.Unclip the bleed hose from the battery box.
7.Unclip the expansion tank from its mounting
bracket, remove the expansion tank cap and
raise the expansion tank vertically 10 cm (4 in).
Retain the tank in this position.
8.Slowly fill the system through the coolant
expansion tank until a steady flow of coolant is
emitted from the bleed hole.
9.Fit the bleed screw, then, with the expansion
tank still raised, continue filling the system until
coolant level reaches the cold level mark on
expansion tank.
10.Fit expansion tank filler cap, fit the expansion
tank to its mounting bracket and clip the bleed
hose to the battery box.
11.Start and run engine until normal operating
temperature is reached, and check for leaks.
12.Switch off engine and allow to cool.
13.Check for leaks and top-up coolant to the cold
level mark on expansion tank

COOLING SYSTEM - V8
26-2-6 DESCRIPTION AND OPERATION
Description
General
The cooling system used on the V8 engine is a pressure relief by-pass type system which allows coolant to circulate
around the cylinder block and the heater circuit when the thermostat is closed. With coolant not passing through the
radiator, this promotes faster heater warm-up which in turn improves passenger comfort.
A coolant pump is located in a housing at the front of the engine and is driven by a drive belt. The pump is connected
into the coolant passages cast in the cylinder block and pumps coolant from the radiator through the cylinder block.
A viscous fan is attached by means of a nut to the coolant pump pulley drive spindle. The fan draws air through the
radiator to assist in cooling when the vehicle is stationary. The fan rotational speed is controlled relative to the running
temperature of the engine by a thermostatic valve regulated by a bi-metallic coil.
The cooling system uses a 50/50 mix of anti-freeze and water.
Thermostat housing
A plastic thermostat housing is located behind the radiator. The housing has three connections which locate the
radiator bottom hose, top hose and coolant pump feed hose. The housing contains a wax element and a spring loaded
by-pass flow valve.
Thermostat - Main valve
The thermostat is used to maintain the coolant at the optimum temperature for efficient combustion and to aid engine
warm-up. The thermostat is closed at temperatures below approximately 82
°C (179°F). When the coolant
temperature reaches approximately 82
°C the thermostat starts to open and is fully open at approximately 96°C
(204
°F). In this condition the full flow of coolant is directed through the radiator.
The thermostat is exposed to 90% hot coolant from the engine on one side and 10% cold coolant returning from the
radiator bottom hose on the other side.
Hot coolant from the engine passes from the by-pass pipe through four sensing holes in the flow valve into a tube
surrounding 90% of the thermostat sensitive area. Cold coolant returning from the engine, cooled by the radiator,
conducts through 10% of the sensitive area.
In cold ambient temperatures, the engine temperature is raised by approximately 10
°C (50°F) to compensate for the
heat loss of 10% exposure to the cold coolant returning from the bottom hose.
By-pass flow valve
The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm-up. When the main valve
is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the
valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the coolant through
the heater matrix only. This provides a higher flow of coolant through the heater matrix to improve passenger comfort
in cold conditions.
When the engine speed increases above idle the coolant pump produces a greater flow and pressure than the heater
circuit can take. The pressure acts on the flow valve and overcomes the valve spring pressure, opening the valve and
limiting the pressure in the heater circuit. The valve modulates to provide maximum coolant flow through the heater
matrix and yet allowing excess coolant to flow into the by-pass circuit to provide the engine's cooling needs at higher
engine rev/min.

COOLING SYSTEM - V8
26-2-8 DESCRIPTION AND OPERATION
Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct coolant into and out of the engine,
radiator and heater matrix. Plastic pipes are used for the bleed and overflow pipes to the expansion tank.
A bleed screw is installed in the radiator top hose and is used to bleed air during system filling. A drain plug is fitted
to each cylinder bank in the cylinder block. These are used to drain the block of coolant.
Coolant pump
1Pulley flange
2Body
3Impeller
4Gallery
5Inlet connection
The coolant pump is attached to the front of the cylinder block with nine bolts and sealed between the pump housing
and the cylinder block with a gasket. The pump comprises a shaft which passes through an alloy housing. The outer
end of the shaft has a flange which allows for the attachment of the pump drive pulley which is secured with three
bolts. The drive pulley is driven by the grooved auxiliary drive belt and rotates at the same speed as the crankshaft.
The inner end of the shaft is fitted with an impeller which draws coolant from the thermostat housing and circulates it
through the galleries in the cylinder block and through the heater matrix.
The shaft is supported on bearings in the housing which are packed with grease and sealed for life. A seal is
positioned in the housing to further protect the bearings from the ingress of coolant. The seal is manufactured from a
synthetic material which will allow for expansion of the casing when hot coolant is present.
The cast alloy housing has a hose connection which provides the attachment for the coolant pump feed hose. The
cast housing connects with galleries in the cylinder block and distributes coolant from the pump impeller into the
galleries and water jackets.