ECU LAND ROVER DISCOVERY 2002 Workshop Manual

STEERING
57-8 DESCRIPTION AND OPERATION
Steering box
The steering box is located behind the first cross member of the chassis and is secured to the chassis rail with four
bolts. The steering box is of the worm and roller type and has a rotary control valve. The steering box is connected to
the steering knuckles of the front road wheels by the drop arm, drag link and track rod. The steering box is lubricated
by the hydraulic fluid in the housing. The input shaft is attached to the steering wheel via the intermediate shaft and
steering column. The drop arm is secured to the output shaft with a nut and tab washer. A ball joint allows movement
between drop arm and drag link, the ball joint is secured with a locknut. The steering box requries approximately 3.5
turns from lock to lock.
As a maintenance aid, an alignment bolt can be used to lock the drop arm at the steering box centre position. The bolt
fits in a groove in the rear face of the drop arm and screws in to a threaded hole on the bottom of the steering box
housing.
Cross section through steering box
1Relief valve stop 2 off
2Relief valve 2 off
3Piston
4Rack
5Housing
6Output shaft
7Roller
8Valve rotor9Torsion bar
10Input shaft
11Pin
12Valve sleeve
13Course spline
14Worm gear
15Spline (worm gear to torsion bar)

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.

STEERING
57-14 DESCRIPTION AND OPERATION
The PAS pump is located on the auxiliary housing, two bolts go through the PAS pump, mounting bracket and into
the auxiliary housing. One bolt also attaches the mounting bracket to the PAS pump, two bolts secure the mounting
bracket to the auxiliary housing. An inlet adaptor pipe with a seal is secured to the bottom of the pump with two bolts.
A drive pulley is attached to the pump drive shaft with three bolts, and is belt driven at a ratio of 1.35 crankshaft
revolutions to 1 of the drive pulley. A coupling on the rear of the PAS pump rotates the water pump impeller located
in the auxiliary housing. Fluid is supplied to 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.
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.
Steering damper
The steering damper is located behind and just below the first cross member of the chassis. The ends of the steering
damper have steel 'eyes' welded on, rubber bushes are installed in each 'eye'. The steering damper is attached
between brackets on the chassis rail and the drag link. Each end of the steering damper is secured by a bolt and
locknut. The hydraulic damper absorbs shocks in the steering, caused by road wheel deflections when operating on
rough terrain.

STEERING
ADJUSTMENTS 57-17
ADJUST ME NTS
Steering box - check and adjust
$% 57.10.13
Check
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove nut securing drag link to drop arm.
3.Using LRT-57-036, break taper joint and
release drag link.
4.Ensure steering is centralised.
5.With the drop arm held, check for rotational
movement at the intermediate shaft universal
joint. If any movement exists, the steering box
requires adjusting.Adjust
1.Loosen lock nut on steering box adjuster and
tighten adjuster until movement is removed at
universal joint.
CAUTION: Ensure that steering box is
centralised before adjustment. Never over
adjust, free play should just be eliminated.
2.When adjustment is correct, hold the adjuster
and tighten adjuster locknut.
3.Turn steering wheel from lock to lock and check
no tightness exists.
4.Fit drag link to drop arm, and tighten nut to 80
Nm (59 lbf.ft).
5.Remove stands and lower vehicle.

STEERING
57-18 ADJUSTMENTS
Hydraulic system - bleed
$% 57.15.02
Bleed
1.Clean PAS fluid reservoir around filler cap and
fluid level indicators.
2.Remove filler cap from PAS fluid reservoir. If
necessary, fill PAS fluid reservoir to upper level
indicator with recommended fluid.

+ CAPACITIES, FLUIDS AND
LUBRICANTS, Fluids.
CAUTION: Ensure no dirt is allowed to enter
the steering reservoir when the cap is
removed.
3.Start engine and run to normal operating
temperature.
4.Position container to catch fluid spillage from
steering box.
5.With engine at idle speed, and an assistant
turning the steering from lock to lock, loosen
bleed screw on top of steering box. Keep PAS
fluid reservoir topped up and allow all air to
bleed from system. When fluid from bleed
screw is free of air, tighten bleed screw.
CAUTION: Do not hold steering at full lock
for longer than 10 seconds.
6.Stop engine.
7.Clean spilled PAS fluid from steering box and
surrounding area.
CAUTION: Power steering fluid will damage
paint finished surfaces. If spilled,
immediately remove fluid and clean area
with water.
8.Check fluid level in PAS fluid reservoir and fill to
upper level mark. If fluid is aerated, wait until
fluid is free from bubbles.
9.Fit PAS fluid reservoir filler cap.
Steering linkage - centralise
$% 57.35.05
The following procedure assumes that the front
wheel alignment is correctly adjusted.
Adjust
1.Raise front of vehicle, and position the road
wheels at straight ahead.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove nut securing drag link to drop arm.
Using tool LRT-57-036 break taper joint and
release drag link from drop arm.
3.Fit centralising bolt to steering box and ensure
that front road wheels are in the straight ahead
position.
4.Loosen clamp bolts on drag link.

STEERING
57-22 ADJUSTMENTS
38.Fit new seal, connect PAS cooler pipe and
tighten union nut to 24 Nm (18 lbf ft).
39. LHD only: Fit turbocharger intercooler feed
pipe and vacuum connection. Fit new seal to air
cleaner. Connect air intake hose and secure
clips. Connect multiplug to MAF sensor.
40.Clean chassis and surrounding area.
41.Fit underbelly panel.

+ EXTERIOR FITTINGS, REPAIRS,
Panel - underbelly.
42.Remove adaptor and hose set from tool LRT-
57-041.
43.Check PAS fluid level.
44.Connect battery earth lead.
Power steering pressure check - V8 LHD
models
$% 57.90.10.01
Check
1.Disconnect battery earth lead.
2.Syphon PAS fluid from reservoir.
3.Raise front of vehicle and support on stands.
4.Turn steering on LH lock.
5.Remove 3 screws securing LH splash shield
and remove shield.
6.Release clip securing PAS pipes.
7.Position absorbent cloth to catch spillage.
8.Position container to collect PAS fluid spillage.

STEERING
ADJUSTMENTS 57-23
9.Release clips and remove air intake hose from
air cleaner housing.
Note: Pre 03 MY air intake hose illustrated.
10.Discard intake 'O' ring and move intake aside
for access.
11.Loosen union securing high pressure pipe to
PAS pump and release pipe.12.Fit adaptor LRT-57-034A to high pressure port
of PAS pump.
13.Fit adaptor LRT-57-035 to existing high
pressure hose.
14.Fit hose LRT-57-002/3 to each adaptor.
15.Fit pressure gauge LRT-57-005 to test valve
LRT-57-001
16.Connect hoses LRT-57-002/3 to LRT-57-001
and tighten unions.
17.Hang pressure gauge in a safe position under
bonnet.
18.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
19.Connect battery earth lead.
20.Start engine and allow air to bleed from PAS
system by turning steering from lock to lock.
Stop engine and check PAS fluid level.
21.Ensure steering system and test equipment are
free from leaks.
22.Maintain maximum fluid level during test.
23.Open the test valve on LRT-57-001 and start
the engine.
24.With the engine at idle, slowly turn the steering
wheel and hold on full lock.
25.Note the pressure reading on LRT-57-005.
26.Repeat the pressure check for the opposite full
lock.
27.Test pressure should be between 21 and 62
bar, (300 to 900) psi. Dependant on road
surface.
28.With the engine at idle, centralise the steering
wheel. Pressure should read 7 bar (100 psi) or
below.
29.Pressures outside the above tolerance
indicates a fault.
30.To determine if fault is in steering pump or
steering box, close the valve on LRT-57-001 for
a maximum of 5 seconds. Pump damage may
occur if test valve is closed for longer periods.
31.If gauge does not register between 75 and 103
bar, (1500 psi), (maximum pump pressure), the
pump is faulty.
32.If maximum pump pressure is correct suspect
the steering box.

STEERING
57-24 ADJUSTMENTS
33.On completion stop engine, disconnect battery
earth lead and syphon fluid from PAS reservoir.
34.Remove test equipment from LRT-57-002.
35.Clean PAS pump and pipe union.
36.Fit new 'O' ring to high pressure pipe, align to
PAS pump and tighten union to 25 Nm (18
lbf.ft).
37.Secure PAS pipes in clip.
38.Using new 'O' ring fit intake hose to air cleaner
and secure clips.
39.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
40.Connect battery earth lead.
41.Start engine and allow air to bleed from PAS
system, by turning steering from lock to lock.
42.Visually check PAS system for leaks.
43.Clean chassis member.
44.Check power steering fluid, if aerated, wait until
fluid is free from bubbles then top-up reservoir
to 'UPPER' level mark.
45.Lower vehicle.
46.Dismantle test equipment.
Power steering pressure check - V8 RHD
models
$% 57.90.10.01
Check
1.Fit gauge and hose LRT-57-005 to valve
assembly LRT-57-001, tighten union.
2.Fit 2 hoses LRT-57-002 to valve assembly
LRT-57-001 and tighten unions.
3.Fit adaptor hoses LRT-57-041 to LRT-57-002
and tighten unions.
4.Disconnect battery earth lead.
5.Remove 5 screws securing front splash shield
to chassis. Remove shield.
6.Clean PAS fluid reservoir around filler cap and
fluid level indicators.

STEERING
ADJUSTMENTS 57-25
7.Syphon PAS fluid from reservoir.
8.Position container to collect PAS fluid spillage.
9.Clean steering box pipe pipe housing.
10.Remove bolt securing pipe clip to steering box.
Leaving the feed pipe from PAS reservoir in
place, release clip and PAS cooler pipe from
steering box. Discard lower 'O' ring.
11.Fit LRT-57-041 adaptor to steering box.
12.Fit PAS cooler pipe to LRT-57-041, align
retaining clip and tighten Allen bolt to 25 Nm (18
lbf.ft).
13.Hang pressure gauge in a safe position under
bonnet.
14.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
15.Connect battery earth lead.
16.Start engine and allow air to bleed from PAS
system by turning steering from lock to lock.
Stop engine and check PAS fluid level.
17.Ensure steering system and test equipment are
free from leaks.
18.Open test valve on LRT-57-001 and start
engine.
19.With the engine at idle, slowly turn the steering
wheel and hold on full lock.
20.Note the pressure reading on LRT-57-005.21.Repeat the pressure check for the opposite full
lock.
22.Test pressure should be between 21 and 62
bar, (300 to 900) psi. Dependant on road
surface.
23.With the engine at idle, centralise the steering
wheel. Pressure should read 7 bar (100 psi) or
below.
24.Pressure outside the above tolerance indicates
a fault.
25.To determine if fault is in steering pump or
steering box, close the valve on LRT-57-001 for
a maximum of 5 seconds. Pump damage may
occur if test valve is closed for longer periods.
26.If gauge does not register between 75 and 103
bar, (1500 psi), (maximum pump pressure), the
pump is faulty.
27.If maximum pump pressure is correct suspect
the steering box.
28.On completion stop engine, disconnect battery
earth lead and syphon fluid from PAS reservoir.
29.Remove test equipment from LRT-57-002.
30.Remove bolt and clip from steering box.
31.Release PAS cooler pipe from LRT-57-041 and
discard 'O' ring. Leaving PAS reservoir oil feed
pipe in place, release LRT-57-041 from
steering box and discard 'O' ring.
32.Fit new 'O' rings to PAS cooler pipe.
33.Fit PAS cooler pipe to steering box, align
retaining clip, fit bolt and tighten to 25 Nm (18
lbf.ft).
34.Remove PAS reservoir filler cap, fill to level
indicator and refit cap.
35.Clean chassis member.
36.Fit splash shield and secure with screws.
37.Connect battery earth lead.
38.Start engine.
39.Start engine and allow air to bleed from PAS
system, by turning steering from lock to lock.
40.Visually check PAS system for leaks.
41.Check power steering fluid, if aerated, wait until
fluid is free from bubbles then top-up reservoir
to 'UPPER' level mark.
42.Visually check PAS system for leaks.
43.Dismantle test equipment.

STEERING
REPAIRS 57-27
REPAIRS
Power steering box - V8
$% 57.10.01
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove front road wheel.
3.Ensure steering wheel is centralised and fit
centralising bolt to steering box. Remove key
from steering lock and engage column lock.
4.Remove 3 bolts securing intermediate shaft
and universal joint.
5.Push intermediate shaft upwards, release and
remove universal joint.
CAUTION: Do not turn the steering wheel
with the intermediate shaft or universal joint
disconnected as damage to the rotary
coupler and the steering wheel switches
may occur.
6.Position container to catch oil spillage.