4 Brush the dust and dirt from the caliper and
pistons, but do not inhale it, as it is a health
hazard. Inspect the dust cover around the
pistons for damage and for evidence of fluid
leaks, which if found will necessitate caliper
overhaul as described in Section 10. Inspect
the anti-rattle plate for corrosion, and if
necessary renew it.
5 If new brake pads are to fitted, the caliper
pistons will need to be pushed back into
their bores, to allow for the extra pad
thickness. Use a C-clamp or suitably-
protected screwdriver as a lever to do this.
Note that, as the pistons are pressed back,
they will displace the fluid in the system,
causing the fluid level in the brake master
cylinder reservoir to rise and possibly
overflow. To avoid this possibility, a small
quantity of fluid should be syphoned from
the reservoir. If any brake fluid is spilt onto
the bodywork, hoses or adjacent
components in the engine compartment,
wipe it clean without delay.
6 Prior to refitting, check that the pads and
the disc are clean. Where new pads are to be
installed, peel the protective backing paper
from them. If the old pads are to be refitted,
ensure that they are correctly located as
noted during their removal.
7 Locate the inner and outer brake pads into
position in the caliper, and refit the upper
retaining pin.
8 Locate the anti-rattle plate in position, and
refit the lower retaining pin.
9 Repeat the procedure on the opposite rear
brake assembly.
10 Before lowering the vehicle, check the
that the fluid level in the brake master
cylinder reservoir is up to the “Maximum”
level mark, and top-up with the specified
fluid type if required. Depress the brake
pedal a few times to position the pads
against the disc, then recheck the fluid level
in the reservoir and further top-up the fluid
level if necessary.
11 Refit the roadwheels, then lower the
vehicle to the ground. Tighten the roadwheel
retaining nuts to the specified torque setting.
12 To allow the new brake pads to bed-in
and reach full efficiency, a running-in period
of approximately 100 miles or so should be
observed before hard use and heavy
braking.
10 Rear brake caliper - removal,
overhaul and refitting
4
Removal
1 Chock the front wheels, then jack up the
rear of the car and support it on axle stands.
Remove the appropriate rear roadwheel.
2 Remove the rear brake pads as described
in Section 9.
3 Fit a brake hose clamp to the flexible brake
hose leading to the rear brake caliper. This will
minimise brake fluid loss during subsequent
operations.
4 Loosen (but do not completely unscrew) the
union on the caliper end of the flexible brake
hose.
5 Undo the two caliper retaining bolts, and
withdraw the caliper from the disc (see
illustration).
6 Support the caliper in one hand, and
prevent the brake hose from turning with the
other hand. Unscrew the caliper from the
hose, making sure that the hose is not twisted
unduly or strained. Once the caliper is
detached, cover or plug the open hydraulic
unions to keep them clean.
Overhaul
7 With the caliper on the bench, wipe away all
traces of dust and dirt, but avoid inhaling the
dust, as it is a health hazard.
8 Remove the pistons from their bores by
applying air pressure from a foot pump into
the caliper hydraulic fluid hose port. In the
event of a high-pressure air hose being used,
keep the pressure as low as possible, to avoid
the pistons being ejected too quickly and
being damaged. Any fluid remaining in the
caliper will probably be ejected with the
pistons.
9 Using a suitable hooked tool, carefully
extract the dust covers from their grooves in
the pistons, and the seals from their grooves
in the caliper bore, but take care not to
scratch or damage the pistons and/or the
bores in the caliper.
10 Clean all parts in methylated spirit or
clean brake fluid, and wipe dry using a clean
lint-free cloth. Inspect the pistons and caliper
bores for signs of damage, scuffing or
corrosion; if these conditions are evident,
renew the caliper assembly.
11 If the components are in satisfactory
condition, a repair kit which includes new
seals and dust covers must be obtained.
12 Lubricate the caliper bores and the seals
with clean brake fluid, and carefully fit the
seals in the caliper bore. Use the fingers only
(no tools) to manipulate them into position in
their grooves. When in position, check that
the seals are not distorted or twisted.
13 Locate the dust covers over the pistons
so that their inner diameters are engaged in
the piston grooves. Insert the pistons into the
caliper. Push the pistons into position in the
bore, and simultaneously press the dust
covers into the caliper so that they are seated
correctly. Take particular care not to distort or
damage the seals or dust cover as they are
fitted.
Refitting
14 Unplug the hydraulic hose, check that the
unions are clean, then reconnect the caliper to
the hose, reversing the disconnection
procedure so that the hose is not twisted or
strained. The hose union connection can be
fully tightened when the caliper is refitted.
15 Slide the caliper over the brake disc, and
secure with the two retaining bolts tightened
to the specified torque.
16 The brake hydraulic hose can now be fully
tightened. When secured, ensure that the
hose does not foul on the wheel arch or
suspension components.
17 Refit the brake pads as described in
Section 9.
18 Top-up the hydraulic fluid level in the
reservoir, and bleed the brake circuit as
described in Section 17.
19 Refit the roadwheel, lower the vehicle to
the ground, and then tighten the wheel nuts to
the specified torque setting.
11 Rear brake disc - inspection,
removal and refitting
2
Note: To prevent uneven braking, BOTH rear
brake discs should be renewed or reground at
the same time.
Inspection
1 Chock the front roadwheels, then jack up
the rear of the vehicle and support it on axle
stands. Remove the appropriate rear
roadwheel.
2 Remove the brake pads as described in
Section 9, then undo the two brake caliper
retaining bolts. Withdraw the caliper from the
disc, and tie it up using string or wire from a
convenient location. Avoid straining the brake
hose.
3 Temporarily refit two of the wheel nuts to
diagonally-opposite studs, with the flat sides
of the nuts against the disc. Tighten the nuts
progressively, to hold the disc firmly.
4 Scrape any corrosion from the disc. Rotate
the disc, and examine it for deep scoring,
grooving or cracks. Using a micrometer,
measure the thickness of the disc in several
places. Light wear and scoring is normal, but
if excessive, the disc should be removed, and
either reground by a specialist, or renewed. If
regrinding is undertaken, the minimum
thickness must be maintained. Obviously, if
the disc is cracked, it must be renewed.
5 Using a dial gauge or a flat metal block and
feeler gauges, check that the disc run-out
10 mm from the outer edge does not exceed
the limit given in the Specifications. To do
this, fix the measuring equipment, and rotate
9•10 Braking system
10.5 Undo the two caliper retaining bolts
and withdraw the caliper from the disc