1997 JAGUAR XJ6 brake

necessary to detach the brake line. If you’re
removing the caliper for overhaul, detach the
hose from the metal line at the frame bracket
(see Section 8), then disconnect the brake line
from the caliper with a flare-nut spanner to
protect the fitting (see illustration). Plug the
metal line to keep contaminants out of the
brake system and to prevent losing brake
fluid.
3Refer to illustration 3.5c and unbolt the
front or rear caliper.
Overhaul
4Before you remove the piston, place a
wood block between the piston and caliper to
prevent damage as it is removed.
5To remove the piston from the caliper,
apply compressed air to the brake fluid hose
connection on the caliper body (see
illustration). Use only enough pressure to
ease the piston out of its bore. Remove the
dust boot.
Warning: Be careful not to place
your fingers between the piston
and the caliper as the piston
may come out with some force.
Be sure to wear eye protection when using
compressed air.
6Inspect the mating surfaces of the piston
and caliper bore wall. If there is any scoring,
rust, pitting or bright areas, renew the
complete caliper unit with a new one.
7If these components are in good condition,
remove the piston seal from the caliper bore
using a wooden or plastic tool (see
illustration). Metal tools may damage the
cylinder bore.
8Remove the caliper guide pins and the
rubber dust boots from the caliper bracket.
9Wash all the components in brake system
cleaner.
10Using the correct rebuild kit for your
vehicle, reassemble the caliper as follows.11Submerge the new rubber seal in clean
brake fluid and refit it in the lower groove in
the caliper bore, making sure it isn’t twisted.
12Coat the piston with clean brake fluid and
stretch the new dust boot over the bottom of
the piston. Hold the piston over the caliper
bore and insert the rubber flange of the dust
boot into the upper groove in the bore. Start
with the side farthest from you and work your
way around toward the front until it is
completely seated. Push the piston into the
caliper bore until it is bottomed in the bore,
then seat the top of the dust boot in the
groove in the piston.
13Lubricate the sliding surfaces of the guide
pins with silicone-based grease (usually
supplied in the kit), then refit the new dust
boots and pins into the caliper bracket.
Refitting
14Refit the caliper by reversing the removal
procedure (see Section 3).
15If the brake hose was disconnected from
the caliper, bleed the brake system (see
Section 9).
5 Brake disc- inspection,
removal and refitting
2
Note:The following procedure applies to both
the front and rear brake discs.
Inspection
1Loosen the wheel nuts, raise the vehicle
and support it securely on axle stands.
Remove the wheel and refit three nuts to hold
the disc in place. If the rear brake disc is being
worked on, release the handbrake.
2Remove the brake caliper as outlined in
Section 4. It is not necessary to disconnect
the brake hose. After removing the caliper,
suspend it out of the way with a piece of wire.
3Visually inspect the disc surface for scoring
or damage. Light scratches and shallow
grooves are normal after use and may not
always be detrimental to brake operation, but
deep scoring - over 0.015 inch - requires disc
removal and refinishing by an automotive
machine shop. Be sure to check both sides of
the disc (see illustration). If pulsating has
9•4 Braking system
4.7 Remove the piston seal from the
caliper bore using a wooden or plastic tool
(metal tools may damage the
cylinder bore)5.3 The brake pads on this vehicle were
obviously neglected, as they wore down to
the rivets and cut deep grooves into the
disc - this disc must be replaced
3261 Jaguar XJ6 4.2 Use a flare-nut spanner to protect the brake hose fitting when
unscrewing it from the caliper
4.5 With the caliper padded to catch the piston, use compressed
air to force the piston out of its bore - make sure your fingers are
not between the piston and the caliper

been noticed during application of the brakes,
suspect disc runout.
4To check disc runout, place a dial indicator
at a point about 1/2-inch from the outer edge
of the disc (see illustration). Set the indicator
to zero and turn the disc. The indicator
reading should not exceed the specified
allowable runout limit. If it does, the disc
should be refinished by an automotive
machine workshop. Note:It is recommended
that the discs be resurfaced regardless of the
dial indicator reading, as this will impart a
smooth finish and ensure a perfectly flat
surface, eliminating any brake pedal pulsation
or other undesirable symptoms related to
questionable discs. At the very least, if you
elect not to have the discs resurfaced, removethe glazing from the surface with emery cloth
or sandpaper using a swirling motion (see
illustration).
5It is absolutely critical that the disc not be
machined to a thickness under the specified
minimum allowable thickness. The disc
thickness can be checked with a micrometer
(see illustration). Then compare your
measurement to the minimum wear (or discard)
thickness stamped into the hub of the disc
after the disc is removed (see illustration).
Removal
6Cut the safety wire from the caliper bracket
mounting bolts (see illustration). On front
caliper brackets, remove the ABS wheelspeed sensor (see illustration), then remove
the caliper bracket bolts and remove the
bracket.
7Remove the disc retaining screw (see
illustration) and remove the disc from the
hub. If the disc sticks, give it a few sharp raps
with a hammer (see illustration). If the disc is
stuck to the hub, spray a generous amount of
penetrant onto the area between the hub and
the disc and allow the penetrant a few
minutes to loosen the rust between the two
components. If a rear disc still sticks, insert a
thin, flat-bladed screwdriver or brake
adjusting tool through the hub flange, rotate
the star wheel on the handbrake adjusting
screw and contract the handbrake shoes (see
illustration).
Braking system 9•5
9
5.4a To check disc runout, mount a dial
indicator as shown and rotate the disc5.4b Using a swirling motion, remove the
glaze from the disc surface with
sandpaper or emery cloth5.5a The disc thickness can be checked
with a micrometer
5.5b Compare your measurement with the
minimum thickness stamped into the disc5.6a Before you can remove the caliper
mounting bracket bolts (arrowed) and the
bracket, you’ll have to cut the safety wire
between them with a pair of diagonal
cutters (rear bracket shown)5.6b On front caliper brackets, remove the
ABS wheel speed sensor bolt (centre
arrow) and pull out the sensor before
removing the bracket bolts (upper and
lower arrows) and bracket
3261 Jaguar XJ6
5.7a Using an impact driver, if necessary,
remove the disc retaining screw, then
remove the disc from the hub5.7c If a rear disc is stuck to the hub,
insert a suitable tool through the hub
flange and retract the handbrake shoes5.7b If the disc is stuck to the hub, give it
a few sharp raps with a hammer

Refitting
8Place the disc on the hub and refit the disc
retaining screw. Tighten the screw securely.
9Refit the caliper mounting bracket, using a
new safety wire on the mounting bolts.
10Refit the brake pads and caliper (see
Section 3). Tighten all fasteners to the torque
listed in this Chapter’s Specifications.
11Refit the wheel and wheel nuts, then lower
the vehicle to the ground. Tighten the wheel
nuts to the specified torque (see Chapter 1
Specifications). Depress the brake pedal a
few times to bring the brake pads into contact
with the disc.
12Adjust the handbrake shoes, if necessary.
13Check the operation of the brakes
carefully, if possible before driving the vehicle
on public roads.
6 Master cylinder- removal,
overhaul and refitting
3
Note:Although master cylinder parts and
rebuild kits are available for most models, we
recommend replacing the master cylinder with
a new or remanufactured unit, if possible.
Removal
1The master cylinder is connected to the
brake servo, which is attached to the pedal
box, in front of the bulkhead on the driver’s
side of the engine compartment.
2Remove as much fluid as you can from the
reservoir with a syringe.
3Place rags under the line fittings and
prepare caps or plastic bags to cover the
ends of the lines once they are disconnected.
Caution: Brake fluid will damage paint.
Cover all body parts and be careful not to
spill fluid during this procedure.
4Disconnect the electrical connector for the
low fluid level warning light (see illustration).
5Loosen the brake line fittings at the mastercylinder (see illustration). Use a flare-nut
spanner to prevent rounding off the nuts. Pull
the brake lines away from the master cylinder
slightly and plug the ends to prevent
contamination.
6Remove the nuts attaching the master
cylinder to the servo (see illustration). Pull
the master cylinder off the studs and lift it out
of the engine compartment. Again, be careful
not to spill fluid as this is done.
Overhaul
7Follow the accompanying photo sequence,
beginning with illustration 6.7a. Stay in order,don’t skip steps, read each caption and study
the photo carefully.
8Once you have dismantled the master
cylinder, clean everything thoroughly, blow
the parts dry with compressed air and
carefully inspect the secondary piston and the
bore of the master cylinder with a bright light.
If the secondary piston or the master cylinder
bore is damaged or worn, renew the master
cylinder with a new or rebuilt unit.
Bench bleeding procedure
9Before refitting a new or rebuilt master
cylinder it should be bench bled. Because it
9•6 Braking system
6.7a Knock out the roll pin that secures
the reservoir to the master cylinder
6.7b Carefully pry off the reservoir by
inserting a screwdriver between the
reservoir and each grommet; this takes
firm pressure, so don’t slip and damage
the reservoir or the master cylinder
6.7c Remove the grommets, noting the
position of each one
6.6 Remove the two master cylinder
mounting nuts
3261 Jaguar XJ6 6.4 Trace the electrical lead back from the reservoir cap and
disconnect the low fluid level sensor
6.5 Loosen the hydraulic brake line fittings with a flare-nut
spanner to protect the corners of the nuts

Braking system 9•7
9
6.7d Pry off the end cap6.7e Locate the stopper pin (arrowed)
inside the forward grommet hole . . .6.7f . . . insert a punch into the pocket of
the primary piston, place the master
cylinder vertically as shown, push down
on the master cylinder to depress the
pistons and pull out the stopper pin
with a magnet
6.7g Remove the primary piston6.7h Remove the secondary piston6.7i If the secondary piston is stuck, rap
the master cylinder on a wood block to
dislodge it
3261 Jaguar XJ6
6.7j Remove the seals and cups from the
pistons - be very careful not to scratch the
piston surface - then wash the secondary
piston with clean brake fluid and inspect it;
if the secondary piston is damaged, you
must renew the master cylinder with a new
or rebuilt unit (a new primary piston is
included with the rebuild kit)6.7l The master cylinder assembly
1 Roll pin
2 Reservoir
3 Grommets
4 End plate
5 Primary piston
6 Secondary piston stopper pin
7 Secondary piston6.7k Refit the new O-ring seals and cups
as shown; make sure the cups on the
primary piston (the one on the left) face
forward as shown (toward the spring), and
the cups on the secondary piston (the one
on the right) face out, away from the piston
(the one on the left faces toward the
primary piston, the one on the right faces
toward the spring)

will be necessary to apply pressure to the
master cylinder piston and, at the same time,
control flow from the brake line outlets, it is
recommended that the master cylinder be
mounted in a vice. Use caution not to clamp
the vice too tightly, or the master cylinder
body might crack.
10Insert threaded plugs into the brake line
outlet holes and snug them down so that
there will be no air leakage past them, but not
so tight that they cannot be easily loosened.
11Fill the reservoir with brake fluid of the
recommended type (see Recommended
lubricants and fluidsin Chapter 1).
12Remove one plug and push the piston
assembly into the master cylinder bore to
expel the air from the master cylinder. A large
Phillips screwdriver can be used to push on
the piston assembly.
13To prevent air from being drawn back into
the master cylinder, the plug must be
replaced and tightened before releasing the
pressure on the piston assembly.
14Repeat the procedure until only brake
fluid is expelled from the brake line outlet
hole. When only brake fluid is expelled, repeat
the procedure with the other outlet hole and
plug. Be sure to keep the master cylinder
reservoir filled with brake fluid to prevent the
introduction of air into the system.
15Since high pressure is not involved in the
bench bleeding procedure, an alternative to
the removal and renewal of the plugs witheach stroke of the piston assembly is
available. Before pushing in on the piston
assembly, remove the plug as described inStep 12. Before releasing the piston, however,
instead of replacing the plug, simply put your
finger tightly over the hole to keep air from
9•8 Braking system
6.7m Apply some clean brake fluid to the
secondary piston and refit it with the slot
oriented with the stopper pin hole, so that
the stopper pin will go through the slot6.7n Apply a coat of clean brake fluid to
the primary piston and refit it into the bore6.7o Using the same technique as in
illustration 6.7f, depress the pistons and
refit the stopper pin
6.7p Refit the end plate as shown, with the
bend in the plate flange aligned with the
groove in the master cylinder flange6.7q Using a hammer and punch, stake
the end plate as shown (there’s a dimple in
the side of the plate for this purpose)6.7r Refit the grommets
3261 Jaguar XJ6
6.7s Align the reservoir pipes with the
grommets as shown . . .
6.7u Refit the reservoir roll pin . . .6.7v . . . and tap it into place
6.7t . . . and squeeze the reservoir and
master cylinder together; make sure the
reservoir is fully seated

being drawn back into the master cylinder.
Wait several seconds for brake fluid to be
drawn from the reservoir into the piston bore,
then depress the piston again, removing your
finger as brake fluid is expelled. Be sure to put
your finger back over the hole each time
before releasing the piston, and when the
bleeding procedure is complete for that outlet,
renew the plug and snug it up before going on
to the other port.
Refitting
16Refit the master cylinder over the studs on
the brake servo and tighten the mounting nuts
only finger tight at this time.
17Thread the brake line fittings into the
master cylinder. Since the master cylinder is
still a bit loose, it can be moved slightly to
allow the fitting threads to start easily. Do not
strip the threads as the fittings are tightened.
18Tighten the brake fittings securely and the
mounting nuts to the torque listed in this
Chapter’s Specifications.
19Fill the master cylinder reservoir with fluid,
then bleed the master cylinder and the brake
system (see Section 9).
20To bleed the master cylinder on the
vehicle, have an assistant pump the brake
pedal several times and then hold the pedal to
the floor. Loosen the fitting nut to allow air and
fluid to escape, then tighten the nut. Repeat
this procedure on both fittings until the fluid is
clear of air bubbles. Test the operation of the
brake system carefully before placing the
vehicle into service.
7 Brake servo-
general information,
removal and refitting
2
General information
1A hydraulic brake servo system assists
braking when the brake pedal is depressed.
The booster unit, located between the brake
pedal box and the master cylinder, is operated
by hydraulic pressure generated by an engine-
driven pump (on early models) or by an electric
pump (on later models). When the engine isrunning, the pump supplies hydraulic pressure
to an accumulator. The accumulator stores and
regulates the pressure to the hydraulic brake
servo. When you depress the brake pedal, the
pressure in the booster helps actuate the
master cylinder, reducing pedal effort.
2The hydraulic brake servo isn’t rebuildable;
if it fails, it must be replaced. Basic operation
can be checked (see Chapter 1, Section 15),
but in-depth testing of the system requires
special tools, so diagnosis is beyond the
scope of the home mechanic. If the system
fails, take it to a dealer service department or
other qualified repair workshop for repairs.
However, if the unit must be replaced, you
can do it yourself as follows.
Removal and refitting
3With the engine off, discharge the hydraulic
accumulator by depressing the brake pedal
several times until it feels hard to depress.
4Remove the master cylinder (see Section 6).
5Clean the area around the return and
supply tube nuts, then disconnect them with a
flare-nut spanner (see illustration). Plug the
lines to prevent dirt from entering the system.
Caution: Even a particle of dirt can damage
the servo system, so be extremely careful
to prevent dirt from entering the system
while the lines are disconnected.
6To disconnect the brake servo pushrod
from the brake pedal, remove the access
plugs from both sides of the pedal box (see
illustration), remove the clevis pin retaining
clip and drive out the clevis pin.
7Remove the four mounting nuts and
remove the brake servo (see illustration).
8Refitting is the reverse of removal. Tighten
the hydraulic line fittings securely.
9When you’re done, adjust the brake light
switch (see Section 13).
8 Brake hoses and lines-
inspection and renewal
4
Inspection
1About every six months, with the vehicleraised and placed securely on axle stands, the
flexible hoses which connect the steel brake
lines with the front and rear brake assemblies
should be inspected for cracks, chafing of the
outer cover, leaks, blisters and other damage.
These are important and vulnerable parts of
the brake system and inspection should be
complete. A light and mirror will prove helpful
for a thorough check. If a hose exhibits any of
the above conditions, renew it with a new one.
Flexible hose renewal
2Clean all dirt away from the ends of the
hose.
3To disconnect the hose at the frame end,
use a second spanner on the hex-shaped
fitting on the end of the flexible hose and
loosen the nut on the metal brake line (see
illustrations). If the nut is stuck, soak it with
penetrating oil. After the hose is disconnected
from the metal line, remove the nut right
above the bracket and detach the hose from
the bracket.
4To detach the flexible hose from the caliper,
simply unscrew it.
5Refitting is the reverse of the removal
procedure. Make sure the brackets are in
good condition and the locknuts are tightened
securely.
Braking system 9•9
9
7.5 Use a flare-nut spanner to loosen the
fittings, then pull the lines back from the
brake servo and plug them to prevent
contamination7.6 Pry off the two rubber caps from the
pedal box7.7 To detach the brake servo from the
pedal box, remove these four nuts
(arrowed) (lower right nut not visible
in this photo)
8.3a To remove a front flexible brake hose
from a metal brake line, use one spanner
to hold the hose fitting just below the
bracket (lower spanner), then break loose
the nut on the metal line (upper spanner);
to disconnect the flex hose from the
bracket, remove the centre nut (arrowed)
just above the bracket
3261 Jaguar XJ6

6Carefully check to make sure the
suspension and steering components do not
make contact with the hoses. Have an
assistant push on the vehicle and also turn the
steering wheel from lock-to-lock during
inspection.
7Bleed the brake system (see Section 9).
Metal brake line renewal
8When replacing brake lines, use the proper
parts only. Do not use copper line for any
brake system connections. Purchase steel
brake lines from a dealer or motor factors..
9Unless you’re using factory renewal brake
lines, you may need a tubing bender to bend
the lines to the proper shape.
10First, remove the line you intend to renew,
lay it on a clean workbench and measure it
carefully. Obtain a new line of the same length
and bend it to match the pattern of the old
line.
Warning: Do not crimp or
damage the line. No bend should
have a smaller radius than
9/16-inch. Make sure the
protective coating on the new line is
undamaged at the bends.
11When refitting the new line, make sure it’s
well supported by the brackets, the routing
matches the original and there’s plenty of
clearance between moving or hot
components.
12After refitting, check the master cylinder
fluid level and add fluid as necessary. Bleed
the brake system as outlined in Section 9 and
test the brakes carefully before driving the
vehicle. Be sure there are no leaks.
9 Brake hydraulic system-
bleeding
2
Warning: Wear eye protection
when bleeding the brake
system. If the fluid comes in
contact with your eyes,
immediately rinse them with water and
seek medical attention.Note:Bleeding the hydraulic system is
necessary to remove any air which has entered
the system during removal and refitting of a
hose, line, caliper or master cylinder.
1It will probably be necessary to bleed the
system at all four brakes if air has entered the
system due to low fluid level or if the brake
lines have been disconnected at the master
cylinder.
2If a brake line was disconnected at only one
wheel, then only that caliper or wheel cylinder
must be bled.
3If a brake line is disconnected at a fitting
located between the master cylinder and any
of the brakes, that part of the system served
by the disconnected line must be bled.
4Bleed the right rear, the left rear, the right
front and the left front caliper, in that order,
when the entire system is involved.
5Remove any residual vacuum from the
servo and pressure in the anti-lock braking
system (if equipped) by applying the brake
about 30 times with the engine off.
6Remove the master cylinder reservoir cover
and fill the reservoir with brake fluid. Refit the
cover. Note:Check the fluid level often during
the bleeding operation and add fluid as
necessary to prevent the fluid level from falling
low enough to allow air into the master
cylinder.
7Have an assistant on hand, as well as a
supply of new brake fluid, an empty clear
plastic container, a length of 3/16-inch clear
tubing to fit over the bleed screws and a
spanner to open and close the bleed screws.
8Beginning at the right rear wheel, loosen the
bleed screw slightly, then tighten it to a point
where it is snug but can still be loosened
quickly and easily.
9Place one end of the tubing over the bleed
valve and submerge the other end in brake
fluid in the container (see illustration).
10Have the assistant pump the brakes a few
times to build pressure in the system, then
hold the pedal firmly depressed.
11While the pedal is held depressed, open
the bleed screw just enough to allow fluid to
flow from the caliper. Watch for air bubbles toexit the submerged end of the tube. When the
fluid flow slows after a couple of seconds,
close the screw and have your assistant
release the pedal.
12Repeat Steps 10 and 11 until no more air
is seen leaving the tube, then tighten the
bleed screw and proceed to the left rear
wheel, the right front wheel and the left
front wheel, in that order, and perform the
same procedure. Be sure to check the fluid in
the master cylinder reservoir frequently.
13Never reuse old brake fluid. It contains
contaminates and moisture which could
damage the braking system.
14Refill the master cylinder with fluid at the
end of the operation.
15Check the operation of the brakes. The
pedal should feel solid when depressed, with
no sponginess. If necessary, repeat the entire
process.
Warning: Do not drive the car if
in doubt about the effectiveness
of the brake system.
10 Handbrake cable-
adjustment
1
1Slowly apply the handbrake and count the
number of clicks at the lever. It should be fully
applied within three to five clicks. If the lever is
still not fully applied by the fifth click, adjust
the handbrake cable as follows:
2Raise the vehicle and place it securely on
axle stands.
3Loosen the locknut (see illustration)and
tighten the cable adjuster until all slack has
been removed. Tighten the locknut. Make
sure the wheels turn freely with the handbrake
lever released
4Lower the vehicle and recheck the
handbrake lever. It should now be properly
adjusted. If it’s now fully applied within three
to five clicks, raise the vehicle again and
readjust the cable at the adjuster.
5Make sure the handbrake holds the vehicle
on an incline.
9•10 Braking system
8.3b The connection (arrowed) for the rear
hose and line is located right above the
mounting bracket for the front corner of
the differential crossmember; remove the
hose as described in the previous
illustration9.9 When bleeding the brakes, a hose is
connected to the bleed screw at the caliper
or wheel cylinder and then submerged in
brake fluid - air will be seen as bubbles in
the tube and container (all air must be
expelled before moving to the next brake)
10.3 To adjust the handbrake cable,
loosen the locknut, then turn the adjuster
to remove any slack in the cable; be sure
to tighten the locknut when the cable is
properly adjusted
3261 Jaguar XJ6

11 Handbrake cable(s)- renewal
2
1Raise the vehicle and place it securely on
axle stands.
Front cable
2Remove the cotter pin, washer and clevis
pin from the forward end of the front cable
(see illustration). Disconnect the forward end
of the front cable from the handbrake lever.
3Follow the cable back to the adjuster lever
and remove the cotter, washer and clevis pin
(see illustration). Remove the front cable.
4Refitting is the reverse of removal.
Intermediate cable
5Remove the cotter pins, washers and clevis
pin from both ends of the intermediate cable
(see illustration). Remove the cable.
6Refitting is the reverse of removal.
Rear cables
7Remove the cotter pin, washer and clevis
pin from the intermediate cable-to-rear cable
yoke (see illustration).
8Disconnect the rear end of each cable from
the handbrake assembly (see illustration).,
then pry the cable out of the carrier.
9Refitting is the reverse of removal.
All cables
10Be sure to adjust the handbrake cable
when you’re done (see Section 10). The rear
wheels should turn freely with the handbrake
lever released.
11Remove the axle stands and lower the
vehicle. Apply the handbrake lever, make sure
it’s fully applied within three to five clicks and
that it holds the vehicle on an incline. If it
doesn’t, readjust it (see Section 10).
12 Handbrake shoes-
check and renewal
2
Warning: Dust created by the
brake system may contain
asbestos, which is harmful to
your health. Never blow it out
with compressed air and don’t inhale any
of it. An approved filtering mask should be
worn when working on the brakes. Do not,
under any circumstances, use petroleum-
based solvents to clean brake parts. Use
brake system cleaner only!
Check
1The handbrake system should be checked
regularly. With the car parked on a hill, apply
the brake, place the transmission in Neutral
and check that the handbrake alone will hold
the car (be sure to stay in the car during this
check). However, every 24 months (or
Braking system 9•11
9
3261 Jaguar XJ6 11.2 To disconnect the forward end of the
front cable from the handbrake lever,
remove this cotter pin, washer
and clevis pin
11.3 To disconnect the rear end of the
front cable from the adjuster lever, remove
this cotter pin, washer and clevis pin
(arrowed)11.5 To disconnect the intermediate cable,
remove the cotter pins, washers and clevis
pins (arrowed) from the adjuster lever
and the yoke
11.7 To disconnect the rear cables and yoke from the
intermediate cable, remove this cotter pin, washer
and clevis pin (arrowed)11.8 The rear handbrake cable-to-handbrake shoe connection is
hidden behind the lower part of the brake backing plate, on the
underside of the carrier (this view is looking straight up from
underneath the carrier). To disconnect either rear handbrake
cable, swing this clip (arrowed) to the side and remove it - the
rear cable is now disconnected