AUX LAND ROVER DISCOVERY 2002 Owner's Guide
Page 592 of 1672
COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-9
Viscous fan
1Idler pulley drive attachment
2Fan blades
3Bi-metallic coil
4Body
The viscous fan provides a means of controlling the speed of the fan relative to the operating temperature of the
engine. The fan rotation draws air through the radiator, reducing engine coolant temperatures when the vehicle is
stationary or moving slowly.
The viscous fan is attached to an idler pulley at the front of the engine which is driven at crankshaft speed by the
auxiliary drive belt. The fan is secured to the pulley by a nut. The nut is positively attached to the fan spindle which
is supported on bearings in the fan body. The viscous drive comprises a circular drive plate attached to the spindle
and driven from the idler pulley. The drive plate and body have interlocking annular grooves with a small clearance
which provides the drive when silicone fluid enters the fluid chamber. A bi-metallic coil is fitted externally on the
forward face of the body. The coil is connected to and operates a valve in the body. The valve operates on a valve
plate with ports that connect the reservoir to the fluid chamber. The valve plate also has return ports which, when the
valve is closed, scoop fluid from the fluid chamber and push it into the reservoir under centrifugal force.
Silicone fluid is retained in a reservoir at the front of the body. When the engine is off and the fan is stationary, the
silicone fluid level stabilises between the reservoir and the fluid chamber. This will result in the fan operating when the
engine is started, but the drive will be removed quickly after the fan starts rotating and the fan will 'freewheel'.
At low radiator temperatures, the fan operation is not required and the bi-metallic coil keeps the valve closed,
separating the silicone fluid from the drive plate. This allows the fan to 'freewheel' reducing the load on the engine,
improving fuel consumption and reducing noise generated by the rotation of the fan.
When the radiator temperature increases, the bi-metallic coil reacts and moves the valve, allowing silicone fluid to
flow into the fluid chamber. The resistance to shear of the silicone fluid creates drag on the drive plate and provides
drive to the body and the fan blades.
Page 609 of 1672
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.
Page 619 of 1672
COOLING SYSTEM - V8
26-2-18 REPAIRS
Thermostat
$% 26.45.09
Remove
1.Drain cooling system.
+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
2.Remove viscous fan.
+ COOLING SYSTEM - V8, REPAIRS,
Fan - viscous.
3.Release 3 clips and disconnect coolant hoses
from thermostat.
4.Remove thermostat.
Refit
1.Position thermostat, connect hoses and secure
with clips.
2.Fit viscous fan.
+ COOLING SYSTEM - V8, REPAIRS,
Fan - viscous.
3.Refill cooling system.
+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
Gasket - coolant pump
$% 26.50.02
Remove
1.Remove auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
2.Drain cooling system.
+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
3.Remove 3 bolts securing pulley to coolant
pump and remove pulley.
4.Release clip and disconnect feed hose from
coolant pump.
Page 620 of 1672
COOLING SYSTEM - V8
REPAIRS 26-2-19
5.Remove 9 bolts securing coolant pump,
remove pump and discard gasket. Refit
1.Clean coolant pump and mating face.
2.Fit new gasket and coolant pump to cylinder
block. Fit bolts and tighten to 24 Nm (18 lbf.ft).
3.Connect feed hose to coolant pump and secure
with clip.
4.Ensure mating faces of coolant pump pulley
and flange are clean. Fit pulley and tighten
bolts to 22 Nm (16 lbf.ft).
5.Fit auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
6.Refill cooling system.
+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.
Page 629 of 1672
MANIFOLDS AND EXHAUST SYSTEMS - TD5
30-1-8 REPAIRS
Gasket - exhaust manifold
$% 30.15.12
Remove
Note: The following procedure covers engines
fitted with or without an EGR cooler. The EGR
cooler is bolted to the front of the cylinder head.
1.Remove turbocharger.
+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Turbocharger.
2. Models with air conditioning: Remove
auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
3. Models with air conditioning: Remove 4 bolts
securing compressor and move to one side.
4.Remove and discard 2 Allen screws securing
EGR pipe to exhaust manifold.
Note: Engine with EGR cooler illustrated.5.Remove 10 nuts securing exhaust manifold to
cylinder head.
6.Remove exhaust manifold and gasket.
Refit
1.Clean exhaust manifold and mating faces.
2.Fit new gasket.Fit exhaust manifold and,
working from the centre outwards, tighten nuts
to 25 Nm (18 lbf.ft) .
3. Models with air conditioning:
Positioncompressor and tighten bolts to 25 Nm
(18 lbf.ft).
4.Position EGR valve pipe, fit new Allen screws
and tighten to 9 Nm (7 lbf.ft).
5.Fit turbocharger.
+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Turbocharger.
6. Models with air conditioning: Fit auxiliary
drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
Page 641 of 1672
MANIFOLDS AND EXHAUST SYSTEMS - V8
30-2-12 REPAIRS
Heat shield - brake servo - With
Secondary Air Injection
$% 30.10.48
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Remove nut securing heat shield bracket to
valance.
4.Remove 2 bolts securing heat shield and
remove heat shield.
Refit
1.Fit heat shield, tightening bolts to 25 Nm (18
lbf.ft) and nut to 10 Nm (7 lbf.ft).
2.Connect battery earth lead.
3.Fit battery cover and secure with fixings.
Gasket - inlet manifold - lower
$% 30.15.08
Remove
1.Remove both rocker covers.
l
+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - LH.
l
+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - RH.
2.Release and disconnect LH injector harness
and multiplugs.
3.Release 3 clips securing top hose and remove
top hose.
4.Remove auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
Page 642 of 1672
MANIFOLDS AND EXHAUST SYSTEMS - V8
REPAIRS 30-2-13
5.Remove 3 bolts securing ACE pump, release
pump and position aside.
6.Remove 2 bolts securing alternator and
remove alternator. 7.Remove 3 bolts securing PAS pump pulley and
remove pulley.
8.Remove jockey pulley.
9.Position tray to catch spillage, release PAS
pump high pressure pipe.
CAUTION: Always fit plugs to open
connections to prevent contamination.
10.Remove bolt securing oil cooling pipe and
release bracket from auxiliary housing.
11.Remove two bolts securing PAS pump.
12.Remove 5 bolts and one nut securing auxiliary
housing. Pull housing forward, release PAS
pump and remove housing.
Page 644 of 1672
MANIFOLDS AND EXHAUST SYSTEMS - V8
REPAIRS 30-2-15
Refit
1.Clean old RTV sealant from cylinder head and
cylinder block notches.
2.Clean mating faces of cylinder block, cylinder
head and inlet manifold.
3.Apply RTV sealant to cylinder head and
cylinder block notches.
4.Fit new gasket seals, ensuring ends engage
correctly in notches.
5.Fit new inlet manifold gasket.
6.Position gasket clamps and fit bolts, but do not
tighten at this stage.
7.Position inlet manifold to engine. Fit manifold
bolts and, working in the sequence shown,
tighten bolts initially to 10 Nm (7 lbf.ft) then to
51 Nm (38 lbf.ft).
8.Tighten gasket clamp bolts to 18 Nm (13 lbf.ft).
9.Connect fuel pipe.
10.Clean top hose outlet pipe mating faces.
11.Fit new 'O' ring to outlet pipe.
12.Position outlet pipe, fit bolts and tighten to 22
Nm (16 lbf.ft).
13.Position alternator, fit bolts and tighten to 45
Nm (33 lbf.ft).
14.Position PAS pump to auxiliary housing and
locate housing on engine. Fit bolts and tighten
to 40 Nm (30 lbf.ft).
15.Fit and tighten auxiliary housing nut to 10 Nm (7
lbf.ft).
16.Fit bolts securing PAS pump and tighten to 22
Nm (16 lbf.ft). 17.Position oil cooling pipe bracket fit bolt and
tighten to 22 Nm (16 lbf.ft).
18.Fit and tighten PAS pump high pressure pipe.
19.Position jockey pulley and tighten bolt to 50 Nm
(37 lbf.ft).
20.Clean PAS pump pulley mating faces.
21.Position PAS pump pulley, fit bolts and tighten
to 22 Nm (16 lbf.ft).
22.Clean ACE pump dowels and dowel holes.
23.Position ACE pump, fit bolts and tighten to 22
Nm (16 lbf.ft).
24.Fit auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
25.Secure injector harness and connect injector
multiplugs.
26.Position top hose and secure clips.
27.Fit rocker covers.
l
+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - LH.
l
+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - RH.
28.Check and top up PAS fluid
Page 899 of 1672
STEERING
57-12 DESCRIPTION AND OPERATION
PAS pump - V8
1Bolt 2 off
2Nut
3Stud
4Auxiliary housing
5PAS pump6Outlet
7Inlet
8Bolt 3 off
9Drive pulley
The PAS pump is located on the auxiliary housing and is attached by two bolts, the bolts go through flanged bushes
in the auxiliary housing. A stud passes through the PAS pump and through a flanged bush in the auxiliary housing,
the auxiliary housing and PAS pump are secured by a nut. As the two bolts and nut are tightened the bushes move
slightly and the flange of each bush clamps the PAS pump. A drive pulley is attached to the pump drive shaft with
three bolts, and is belt driven at a ratio of 1.4 crankshaft revolutions to 1 of the drive pulley. Fluid is drawn into the
PAS pump inlet from the reservoir through a flexible hose at low (suction) pressure. Fluid at high pressure from the
PAS pump outlet is supplied to the rotary control valve on the steering box.
Page 900 of 1672
STEERING
DESCRIPTION AND OPERATION 57-13
The PAS pump is a roller vane type and has an internal pressure regulator and flow control valve. The roller vanes
can move in slots in the pumps rotor and are moved outwards by centrifugal force as the pump rotates. The pump
rotor rotates in the pump housing, the internal shape of the housing forms a 'cam' shape. Due to the 'cam' shape the
volume of the housing decreases between the inlet and outlet ports.
As the pump rotor rotates towards the pump inlet the volume between the roller vanes and the pump housing
increases, this action causes a depression in the chamber between the pump roller vanes and the housing. As the
rotation continues the chamber is opened to the pump inlet, and the depression in the chamber causes fluid to be
drawn in. The roller vanes continue past the inlet port, closing off the inlet port and trapping the fluid in the chamber
between the rollers and the pump housing.
The internal 'cam' shape of the pump housing causes the rollers to move closer together as the pump rotor rotates
towards the outlet port. The reduced volume of the chamber between the roller vanes causes the fluid to become
pressurised. When the chamber is opened to the outlet port of the pump the fluid escapes at high pressure. The roller
vanes continue turning and go past the outlet port, closing off the chamber between the two roller vanes.
As rotation continues the inlet sequence begins again. The inlet and pressurisation/outlet sequences continue as the
pump rotates, and is repeated between each two roller vanes. The pump is a positive displacement type and the
potential pump output increases with engine (drive pulley) speed. The pressure relief and flow control valve regulates
flow/pressure by diverting fluid back to the pump inlet through internal recirculation passages in the pump body.
PAS pump - diesel
1Drive pulley
2Mounting bracket
3Bolt 2 off
4Bolt
5PAS pump
6Coupling7Auxiliary housing
8Outlet
9Inlet adaptor pipe and seal
10Bolt 2 off
11Bolt 2 off
12Bolt 3 off