1999 LAND ROVER DISCOVERY air bleeding

CONTENTS
CONTENTS 15
FRONT SUSPENSION.............................................................................. 60-1
DESCRIPTION AND OPERATION
Front suspension component layout (ACE torsion bar shown) ....................................................... 60-1
Front suspension components (ACE torsion bar shown) ................................................................ 60-2
Description ...................................................................................................................................... 60-4
DESCRIPTION AND OPERATION
ACE system component layout ....................................................................................................... 60-7
ACE system control diagram .......................................................................................................... 60-8
Description - ACE ........................................................................................................................... 60-9
Operation ........................................................................................................................................ 60-22
ADJUSTMENTS
ACE hydraulic system bleeding ..................................................................................................... 60-25
Fluid level check - ACE system ...................................................................................................... 60-25
REPAIRS
Bushes - Panhard rod ................................................................................................................... 60-27
Ball joint - upper - steering knuckle ............................................................................................... 60-28
Ball joint - lower - steering knuckle ................................................................................................. 60-29
Steering knuckle ........................................................................................................................... 60-30
Road spring - front ........................................................................................................................ 60-32
Wheel hub ....................................................................................................................................... 60-33
Damper - front ............................................................................................................................... 60-35
Bushes - radius arm ...................................................................................................................... 60-37
ECU - ACE ..................................................................................................................................... 60-39
Accelerometer - ACE - upper ........................................................................................................ 60-40
Accelerometer - ACE - lower ........................................................................................................ 60-40
Pump - ACE - V8 ............................................................................................................................ 60-41
Pump - ACE - diesel ....................................................................................................................... 60-42
Valve block - ACE ......................................................................................................................... 60-44
Filter - high pressure - ACE .......................................................................................................... 60-47
Pressure transducer - ACE ........................................................................................................... 60-48
Solenoid - pressure control valve - ACE ....................................................................................... 60-49
Solenoid - directional control valve - ACE ..................................................................................... 60-49
Pipe assembly - valve block to front actuator - ACE ...................................................................... 60-50
Pipe assembly - pump or reservoir to valve block - ACE - V8 ....................................................... 60-52
Pipe assembly - pump or reservoir to valve block - ACE - diesel .................................................. 60-55
Pipe assembly - valve block to rear actuator - ACE ........................................................................ 60-59
Actuator - front - ACE .................................................................................................................... 60-61
Bushes - front long arm - ACE ........................................................................................................ 60-63

CONTENTS
CONTENTS 17
BRAKES ................................................................................................... 70-1
DESCRIPTION AND OPERATION
Brake system control component layout ......................................................................................... 70-1
Brake system control diagram ........................................................................................................ 70-2
Brake system hydraulic component layout ..................................................................................... 70-4
Description ...................................................................................................................................... 70-5
Operation ........................................................................................................................................ 70-20
DESCRIPTION AND OPERATION
Handbrake component layout ......................................................................................................... 70-25
Description ...................................................................................................................................... 70-26
ADJUSTMENTS
Handbrake .................................................................................................................................... 70-29
Brake system bleeding ................................................................................................................... 70-30
REPAIRS
Brake disc - front .......................................................................................................................... 70-33
Brake disc - rear ............................................................................................................................ 70-34
Master cylinder - brake ................................................................................................................. 70-35
Cable - handbrake ........................................................................................................................ 70-36
Switch - brake light ........................................................................................................................ 70-37
Brake pads - front ......................................................................................................................... 70-38
Brake pads - rear .......................................................................................................................... 70-39
Brake shoes - handbrake ................................................................................................................ 70-40
Servo - brake .................................................................................................................................. 70-42
Vacuum pump - servo ..................................................................................................................... 70-43
Housing - caliper - front ................................................................................................................. 70-45
Housing - caliper - rear ................................................................................................................. 70-46
ECU - Self levelling and anti locking brakes (SLABS) ................................................................. 70-47
Sensor – ABS – front ..................................................................................................................... 70-48
Sensor – ABS – rear ....................................................................................................................... 70-48
Modulator unit - ABS ...................................................................................................................... 70-49
Switch - Hill descent control ............................................................................................................ 70-50
Switch - handbrake ....................................................................................................................... 70-50

MAINTENANCE
PROCEDURES 10-7
Road wheel speed sensors
Inspect
Front wheel
Rear wheel
1.Inspect each sensor harness for damage.
Brake fluid
Replace
1.Replace brake fluid.

+ BRAKES, ADJUSTMENTS, Brake
system bleeding.
Fuel filter - diesel engine
Replace
1.Replace filter element.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Element - fuel filter.
Fuel filter sedimenter
Drain
1.Position suitable container beneath fuel filter.
2.Disconnect multiplug from sedimenter.
3.Rotate sedimenter anti-clockwise until water
flows from drain tube.
4.Allow to drain until diesel fuel flows from drain
tube.
5.Rotate sedimenter fully clockwise.
6.Connect multiplug.

CLUTCH - V8
ADJUSTMENTS 33-2-11
ADJUST ME NTS
Clutch hydraulic system - bleed
$% 33.15.01
CAUTION: Ensure the fluid in the reservoir is
maintained between the minimum and maximum
levels throughout the bleed procedure using new
brake fluid.
CAUTION: Brake fluid will damage paint finished
surfaces. If spilled, immediately remove fluid and
clean area with water.
Bleeding
1.Top up reservoir.
2.Raise the front of the vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
3.Connect tube to bleed screw on clutch slave
cylinder and submerge free end in a clear
container containing brake fluid.
4.Loosen bleed screw, then apply steady
pressure to the clutch pedal, depressing it
through its full stroke. Allow the pedal to return
unassisted.
5.Repeat the procedure until a flow of clean, air-
free fluid is purged into the container.
6.Hold the pedal to the floor and tighten the
clutch bleed screw to 9 Nm (7 lbf.ft).
7.Check and top up reservoir.
CAUTION: Never re-use fluid that has been
bled from the system.
8.Remove stands and lower the vehicle.

FRONT SUSPENSION
DESCRIPTION AND OPERATION 60-11
The ACE system uses a semi-synthetic hydraulic fluid which is the same as the fluid used for the PAS system. The
total capacity of the ACE system is 1.62 litres (0.42 US Gallons).
CAUTION: The ACE hydraulic system is extremely sensitive to the ingress of dirt or debris. The smallest
amount could render the system unserviceable. It is imperative that the following precautions are taken.
lACE components are thoroughly cleaned externally before work commences;
lall opened pipe and module ports are capped immediately;
lall fluid is stored in and administered through clean containers.
In the event of an ECU or hydraulic failure the system will fail safe to a 'locked bars' condition. The 'locked bars'
condition will allow the torsion bars to operate in a similar manner as conventional 'passive' anti-roll bars. Prolonged
cornering forces will allow a progressive increase in roll angle due to hydraulic leakage through the actuators and
valve block. Failures will be relayed to the driver by the illumination of the ACE warning lamp in the instrument pack.
Faults are recorded by the ECU and can be retrieved using TestBook.
When the ignition switch is moved to position II, the warning lamp will illuminate for two seconds to check functionality.
The warning lamp functionality can also be checked using TestBook.
TestBook must also be used to perform a bleeding procedure after maintenance operations have been performed to
ensure that complete system bleeding is performed. Trapped air in the system can seriously reduce the system
performance.
Fluid reservoir
The moulded plastic fluid reservoir is mounted on the left hand side of the engine compartment on a bracket which is
attached to the inner wing. The reservoir is dual purpose, being divided into two separate chambers; one for the ACE
system and one for the PAS system. Each chamber has its own filler neck and cap and is identified by moulded
lettering on the reservoir adjacent to each filler.
A non-serviceable filter assembly is fitted in the base of each chamber. The filter is made from fine stainless steel
mesh which is moulded into the body of the reservoir. The filter removes particulate matter from the fluid before it is
drawn into the hydraulic pump.
Upper and lower fluid level marks are moulded onto the reservoir body. The capacity of the ACE reservoir chamber
to the upper level mark is 0.5 litre (0.13 US Gallon).

FRONT SUSPENSION
60-46 REPAIRS
7.Remove 3 bolts securing valve block to
chassis.
8.Release front pipes and clamping plate from
valve block and remove valve block.
CAUTION: Always fit plugs to open
connections to prevent contamination.
NOTE: Keep pipes assembled to clamping
plate to maintain correct pipe positions for
refitting.
9.Remove 6 bushes from valve block. Refit
1.Fit 6 bushes to valve block.
2.Ensure valve block and pipe connections are
clean.
3.It is important that the pipe ends are in good
condition to achieve a seal.
4.Position valve block and connect front pipes
and clamping plate. To avoid damage to
seals, keep pipes square to valve block. Fit
and tighten bolts securing valve block to
chassis to 18 Nm (13 lbf.ft).
CAUTION: Ensure pipes are installed in
their correct ports or serious system
damage will occur.
5.Fit and tighten nuts securing front clamping
plate to valve block to 21 Nm (15 lbf.ft).
6.Fit bolt securing front pipe clip to chassis and
tighten to 6 Nm (4.4 lbf.ft).
7.Connect rear pipes and clamping plate to valve
block. To avoid damage to seals, keep pipes
square to valve block. Fit and tighten nuts
securing clamping plate to valve block to 21 Nm
(15 lbf.ft).
CAUTION: Ensure pipes are installed in
their correct ports or serious system
damage will occur.
8.Fit bolts securing rear pipe clips to chassis and
tighten to 6 Nm (4.4 lbf.ft) .
9.Connect 4 multiplugs to valve block.
10.If the same valve block has been refitted, renew
ACE high pressure filter.

+ FRONT SUSPENSION, REPAIRS,
Filter - high pressure - ACE.
11.Bleed ACE hydraulic system.

+ FRONT SUSPENSION,
ADJUSTMENTS, ACE hydraulic system
bleeding.
12.Lower vehicle.

FRONT SUSPENSION
REPAIRS 60-51
9.Remove 2 nuts securing pipe clamping plate to
valve block.
10.Release clamping plate and pipes from valve
block. Remove collets and release pipes from
clamping plate.
CAUTION: Always fit plugs to open
connections to prevent contamination.
11.Remove 2 cap nuts securing pipes to ACE
actuator. Disconnect pipes and discard sealing
washers.
CAUTION: Always fit plugs to open
connections to prevent contamination.
12.Release pipes from isolator above chassis RH
front outrigger.
13.Remove pipe assembly.Refit
1.Position pipe assembly.
2.Locate pipes in isolator above chassis RH front
outrigger. Fit cable tie around isolator to secure
pipes.
3.Ensure valve block and pipe connections are
clean.
4.Fit collets and pipes to clamping plate.
5.Connect pipes to valve block. To avoid seal
damage, keep pipes square to valve block.
Fit and tighten nuts securing clamping plate to
valve block to 21 Nm (15 lbf.ft).
CAUTION: Ensure pipes are installed in
their correct ports or serious system
damage will occur.
6.Fit pipe clamps. Secure to chassis with bolt and
to bracket on suspension turret with nut.
7.Connect pipes to ACE actuator with cap nuts
and new sealing washers Tighten cap nuts to
29 Nm (21 lbf.ft). Ensure pipes are not under
tension or kinked.
8.Secure harness to suspension turret.
9.Fit splash shield and secure with screws.
10.Fit RH wheel arch liner extension and secure
with screws.
11.Renew ACE high pressure filter.

+ FRONT SUSPENSION, REPAIRS,
Filter - high pressure - ACE.
12.Fit road wheel(s) and tighten nuts to 140 Nm
(103 lbf.ft).
13.Refill and bleed ARC system.

+ FRONT SUSPENSION,
ADJUSTMENTS, ACE hydraulic system
bleeding.
14.Lower vehicle.

FRONT SUSPENSION
60-60 REPAIRS
7.Remove 2 cap nuts securing pipes to ACE rear
actuator. Disconnect pipes, remove and
discard sealing washers.
CAUTION: Always fit plugs to open
connections to prevent contamination.
8.Remove 2 nuts securing rear pipe clamping
plate. Release clamping plate and pipes from
valve block.
CAUTION: Always fit plugs to open
connections to prevent contamination.
9.Remove pipe assembly.
10.Remove collets and clamping plate from rear
pipes. Refit
1.Ensure valve block and pipe connections are
clean.
2.Install clamping plate and collets on rear pipes.
3.Position pipe assembly to vehicle and connect
pipes and clamping plate to valve block. To
avoid damage to seals, keep pipes square
to valve block. Fit and tighten nuts securing
clamping plate to valve block to 21 Nm (15
lbf.ft).
CAUTION: Ensure pipes are installed in
their correct ports or serious system
damage will occur.
4.Fit bolts securing rear pipe clips to chassis and
tighten to 6 Nm (4.4 lbf.ft).
5.Connect pipes to actuator with cap nuts and
new sealing washers. Tighten cap nuts to 29
Nm (21 lbf.ft). Ensure pipes are not under
tension or kinked.
6.Ensure washer is in place on lower ball joint of
each anti-roll bar link, then connect lower ball
joints to axle and tighten nuts to 100 Nm (74
lbf.ft).
7.Renew ACE high pressure filter.

+ FRONT SUSPENSION, REPAIRS,
Filter - high pressure - ACE.
8.Bleed ACE hydraulic system.

+ FRONT SUSPENSION,
ADJUSTMENTS, ACE hydraulic system
bleeding.
9.Lower vehicle.