engine LAND ROVER DISCOVERY 1999 Workshop Manual
Page 716 of 1529
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.
Page 717 of 1529
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.
Page 718 of 1529
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.
Page 722 of 1529
STEERING
REPAIRS 57-29
12. RH drive models with ACE: Position ACE
control arms to access steering box bolts.
13.With assistance remove 4 securing bolts and
remove steering box.
14.Remove centralising bolt from steering box. Refit
1.Fit centralising bolt to steering box.
2. With assistance, position steering box, fit bolts
and tighten to 90 Nm (66 lbf.ft).
3. RH drive models with ACE: Ensure washer is
in place on lower ball joint of anti-roll bar link,
then connect lower ball joint to axle. Tighten nut
to 100 Nm (74 lbf.ft).
4.Position drag link, fit nut and tighten to 80 Nm
(59 lbf.ft).
5.Position Panhard rod, fit bolt and nut and
tighten to 230 Nm (170 lbf.ft).
6.Clean PAS pipe ends and 'O' ring recess.
7.Lubricate new 'O' rings for PAS pipes with clean
PAS fluid.
8.Fit 'O' rings to PAS pipes and position pipes in
steering box. Fit PAS pipe bracket and tighten
bolt to 22 Nm (16 lbf.ft).
9. RHD models: Fit oil filter and housing:
lClean oil filter housing and engine mating
faces.
lLubricate new 'O' ring with clean engine oil
and fit to housing.
lPosition oil filter housing and tighten bolts to
9 Nm (7 lbf.ft).
10.Ensure steering wheel is centralised. Fit
universal joint between steering box and
intermediate shaft and tighten bolts to 25 Nm
(18 lbf.ft).
11.Remove centralising bolt from steering box.
12.Fit road wheel(s) and tighten nuts to 140 Nm
(103 lbf.ft)..
13.Remove stand(s) and lower vehicle.
14.Check and top up engine oil.
15.Bleed PAS system.
+ STEERING, ADJUSTMENTS,
Hydraulic system - bleed.
16.Centralise steering linkage
+ STEERING, ADJUSTMENTS,
Steering linkage - centralise.
Page 725 of 1529
STEERING
57-32 REPAIRS
17.Remove securing nut and bolt and release
Panhard rod.
18.Remove nut securing drag link to drop arm.
Using LRT-57-036, break taper joint and
release drag link. 19. Models with ACE: Remove nut securing anti-
roll bar link lower ball joint and release joint.
20.With assistance, remove 2 nuts and bolts
securing LH engine mounting to chassis.
Page 726 of 1529
STEERING
REPAIRS 57-33
21.With assistance remove 2 nuts and bolts
securing RH engine mounting to chassis.
22.Support the engine weight on a jack.
CAUTION: To prevent damage to
components, cushion the jack pad with a
block of wood or hard rubber.
23.Raise the engine sufficiently to allow the
steering box to clear the sump.
24. Models with ACE: Position ACE control arms
to access steering box bolts. 25.With assistance remove 4 bolts securing
steering box and remove steering box.
26.Remove centralising bolt from steering box.
Refit
1.Fit centralising bolt to steering box.
2.With assistance, position steering box, fit bolts
and tighten to 90 Nm (66 lbf.ft).
3.Lower the engine onto its mountings. Fit engine
mounting bolts and tighten to 85 Nm (63 lbf.ft).
4. Models with ACE: Ensure washer is in place
on lower ball joint of anti-roll bar link, then
connect lower ball joint to axle. Tighten nut to
100 Nm (74 lbf.ft).
5.Position drag link, fit nut and tighten to 80 Nm
(59 lbf.ft).
6.Position Panhard rod, fit bolt and nut and
tighten to 230 Nm (170 lbf.ft).
7.Position coolant rail and secure with clips and
bolt.
8.Fit coolant hoses and secure with clips.
9. Models with ACE: Fit and tighten bolt
securing ACE pipes to chassis.
10.Clean PAS pipe ends and 'O' ring recess.
11.Lubricate new 'O' rings for PAS pipes with clean
PAS fluid.
12.Fit 'O' rings to PAS pipes and position pipes in
steering box. Fit PAS pipe bracket and tighten
bolt to 22 Nm (16 lbf.ft).
13.Ensure steering wheel is centralised. Fit
universal joint between steering box and
intermediate shaft and tighten bolts to 25 Nm
(18 lbf.ft).
14.Remove centralising bolt from steering box.
15.Fit intercooler to turbo hose and secure with
clips.
16.Fit road wheel(s) and tighten nuts to 140 Nm
(103 lbf.ft).
17.Remove stand(s) and lower vehicle.
18.Connect battery earth lead.
19.Fit battery cover.
20.Refill cooling system.
+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
21.Bleed PAS system.
+ STEERING, ADJUSTMENTS,
Hydraulic system - bleed.
22.Centralise steering linkage
+ STEERING, ADJUSTMENTS,
Steering linkage - centralise.
Page 734 of 1529
STEERING
REPAIRS 57-41
Refit
1.Position PAS pump to auxiliary housing and
locate housing to engine. Fit and tighten
auxiliary housing bolts to 40 Nm (30 lbf.ft).
2.Tighten auxiliary housing nut to 10 Nm (7 lbf.ft).
3.Fit bolts securing PAS pump and tighten to 22
Nm (16 lbf.ft).
4.Position PAS pump pipe bracket, fit and tighten
bolt to 22 Nm (16 lbf.ft).
5.Fit and tighten PAS pump pressure pipe.
6.Fit PAS pump inlet hose and secure with clip.
7.Position jockey pulley and tighten bolt to 50 Nm
(37 lbf.ft).
8.Clean PAS pump pulley mating faces.
9.Position PAS pump pulley, fit bolts and tighten
to 22 Nm (16 lbf.ft).
10. Models with ACE: Clean ACE pump dowels
and dowel holes. Position ACE pump, fit bolts
and tighten to 25 Nm (18 lbf.ft).
11. Models with A/C: Clean A/C compressor
dowels and dowel holes. Position A/C
compressor, fit bolts and tighten to 22 Nm (16
lbf.ft).
12.Position air intake hose and secure with clips.
13.Secure harness to air intake hose with new
cable tie.
14.Fit auxiliary drive belt.
+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive..
15.Bleed PAS system.
+ STEERING, ADJUSTMENTS,
Hydraulic system - bleed.
Page 750 of 1529
FRONT SUSPENSION
DESCRIPTION AND OPERATION 60-5
Coil springs
Coil springs are fitted to the front axle of the vehicle. The front springs differ between petrol and Diesel variants. Each
spring is retained at its base by the lower spring seat. The top of each spring is located in the upper spring seat
isolator. The upper spring seat is manufactured from natural rubber , with a bonded metal plate and four bonded studs
which provide for the attachment of the damper turret. The rubber isolator reduces noise transmitted to the chassis
and body from the suspension.
The coil springs must be installed correctly. The bottom coil of the spring locates in a recess in the lower spring seat.
The top coil of the spring is ground flat to locate the upper spring seat isolator.
Coil Spring Specifications – Models up to 03 Model Year
The front springs on petrol variants are manufactured from carbon chrome 13.9 mm (0.55 in) diameter bar. The spring
has 7.6 coils and a free length of 377 mm (14.8 in). The petrol front spring is identified by a pink and orange stripe
painted on a number of coils.
The front springs on Diesel variants are manufactured from carbon chrome 13.9 mm (0.55 in) diameter bar. The spring
has 7.6 coils and a free length of 383 mm (15.0 in). The Diesel front spring is identified by a white and purple stripe
painted on a number of coils.
Coil Spring Specifications – Models from 03 Model Year
The introduction of the 03MY vehicle introduced a range of additional spring fitments. These were introduced to cover
the introduction of the 4.6l V8 engine, the fitment of a front mounted winch and to optimise the vehicle trim heights.
The coil springs are manufactured from silicon manganese 13.8 mm or 13.9 mm (0.54 in or 0.55 in) diameter bar. The
following spring data table shows the colour codes, number of coils and spring free length.
Spring Data
The following table shows spring fitment applicablity.
Spring Fitment Applicability
The following table shows standard springs and uprated springs required when a front winch is fitted.
Winch Fitment Spring Applicability
Colour Code Total No. of Coils Free Length
Red/Purple 7.4 371 mm (14.6 in)
Yellow/Purple 7.4 378.4 mm (14.9 in)
Blue/Purple 7.4 365 mm (14.4 in)
Grey/Purple 7.4 387 mm (15.2 in)
Purple/Purple 7.4 373.8 mm (14.7 in)
Yellow/Orange 7.4 394.6 mm (15.5 in)
Green/Orange 7.4 382.6 mm (15 in)
Pink/Brown 7.6 405.6 mm (15.9 in)
Left Hand Drive Right Hand Drive
RH side LH side RH side LH side
Red/Purple Red/Purple Yellow/Purple Blue/Purple
Yellow/Purple Yellow/Purple Grey/Purple Purple/Purple
Grey/Purple Grey/Purple Yellow/Orange Green/Orange
Standard Spring Winch Fitted Spring
RH Side LH Side Both Sides
Red/Purple Red/Purple Grey/Purple
Yellow/Purple Blue/Purple Yellow/Orange
Yellow/Purple Yellow/Purple Yellow/Orange
Grey/Purple Purple/Purple Green/Orange
Grey/Purple Grey/Purple Green/Orange
Yellow/Orange Green/Orange Pink/Brown
Page 753 of 1529
FRONT SUSPENSION
60-8 DESCRIPTION AND OPERATION
ACE system control diagram
1Upper accelerometer
2Lower accelerometer
3Pressure transducer
4Directional control valve
5Directional control valve
6Pressure control valve
7Instrument pack warning lamp
8Diagnostic socket9Reverse lamp switch
10SLABS ECU
11Engine Control Module (ECM)
12Ignition feed
13ACE relay
14Battery supply
15ACE ECU
M60 0589B
12
5
4
3
6
7
8
9
10
11
12
13
14
15
Page 755 of 1529
FRONT SUSPENSION
60-10 DESCRIPTION AND OPERATION
ACE system
aDirection of travel - Right hand bend
bBody roll
cAxle roll
dTyre squash
eTorsion/Anti-roll barfDirection of torsion/anti-roll bar twist
gCoil springs
hBody roll angle
iAxle roll angle
jReduced body roll angle with ACE system
The system is electrically and hydraulically operated with all operations controlled by an ACE ECU located behind the
glovebox in the passenger side footwell. The ACE system comprises front and rear torsion bars and actuators, two
accelerometers, ECU, hydraulic pump, valve block and a fluid reservoir.
The ACE system gives improved vehicle handling and suspension characteristics and is active for both on and off-
road driving. This is achieved by hydraulic actuators applying torque to the front and rear torsion bars in response to
lateral forces sensed by accelerometers. The ACE system prevents body roll with cornering forces of up to 0.4 g. From
0.4 g there is a progressive increase in body roll but significantly lower than a passive system. A passive system will
have a progressive increase in roll angle as soon as cornering forces are applied and will have a higher roll angle than
the ACE system for the same cornering force.
The ACE system can also detect if the vehicle is driven off-road. If off-road conditions are detected the ACE system
operation will be reduced or completely disabled at a speed of 25 mph (40 km/h) or less.
Lateral acceleration of the body is sensed by two accelerometers and signals are transmitted to the ECU. The engine
driven hydraulic pump supplies a constant hydraulic flow to the valve block. Two directional control valves are
solenoid operated by the ECU and these supply fluid to the applicable side of each actuator to apply an equal and
opposite force to the torsion bar. In operation the ACE system maintains the attitude of the vehicle body when
cornering.