9•10 Braking system
6.26a Refit the carrier to the hub
16 Dry the components straight after
cleaning, using compressed air or a clean, lint-
free cloth. Use compressed air to blow the
fluid passages clear. If reassembly is not going
to be carried out immediately, remember to
refit a dust cap to the brake hose tapping.
17 Examine all components closely, and
renew any that are worn or damaged. Check
particularly the cylinder bore and piston; if they
are scratched, worn or corroded in any way,
they should be renewed (note that this means
the renewal of the whole hydraulic body
assembly). Check also the condition of the
guide pins and their bores in the hydraulic
body; both pins should be free from damage
and corrosion. After cleaning, they should
form a reasonably tight sliding fit in their
corresponding bores. If they cause the caliper
to jam or stick, they may have distorted
through overheating - check them for warpage
against a straight edge. Renew any
component whose condition is doubtful.
18 If the assembly is fit for further use, obtain
an appropriate repair kit; the components are
available from Saab dealers in various
19 Renew all rubber seals, dust covers and
caps disturbed on dismantling as a matter of
course; the old items should never be re-used.
20 Before reassembly, ensure that all
components are completely clean and dry.
21 Lubricate the new piston seal and dust
cap with the grease provided in the kit.
22 Fit the new piston seal into its seat in the
cylinder - do not use any tools when doing
23 Fit the new dust cap to the piston; slide it
over the end that contacts the brake pad, then
pull it down to the other end of the piston.
24 Push the piston into the cylinder bore, and
retract it fully by turning the adjusting screw
anti-clockwise with a 4 mm Allen key.
25 Push the skirt of the dust cap over the lip
on the edge of the cylinder. Ensure that it is
firmly seated, then fit the retaining ring.
26 Refit the handbrake lever return spring
onto its pivot. Ensure that one end engages
with the lever itself, and the other braces
against the casting.
27 Fit the two rubber bushes and guide pin
6.26b Apply a quantity of thread-locking
compound to the retaining bolts, then
tighten them to the specified torque
28 Refit the carrier to the hub assembly -
apply a quantity of thread-locking compound
to the retaining bolts, then insert and tighten
them to the specified torque (see
29 Reconnect the hydraulic body to the brake
hose by threading the hose union into the
tapping (after removing the dust cap), holding
the hose stationary and rotating the hydraulic
body. Do not fully tighten the union at this
30 Refer to Section 4 for details of fitting the
brake pads and reconnecting the handbrake
cable. Do not refit the roadwheel at this point.
31 Tighten the brake pipe union securely.
Remove the brake hose clamp tool. Referring
to Section 2, bleed the system to expel the air
that will have entered the brake hose when the
caliper was removed. If suitable precautions
were taken to minimise fluid loss, it should
only be necessary to bleed the system at that
32 Refer to Chapter 1 and adjust the
operation of the handbrake.
33 Refit the roadwheel, lower the vehicle to
the ground, and tighten the bolts to the
Warning: Refer to the warning
notes at the start of Sections 2
and 3 regarding the safe handling
of brake system components.
1 Park the vehicle on a firm, level surface,
then chock the rear wheels and apply the
handbrake. Raise the front of the vehicle, rest
it securely on axle stands, and remove the
front roadwheels. Refer to "Jacking, towing
and wheel changing" for guidance.
2 Rotate the brake disc by hand, and examine
the whole of the surface area swept by the
brake pads, on both sides of the disc. Note: It
will be necessary to remove the caliper
hydraulic body to allow an adequate
7.11 Brake disc runout measurement -
DTI gauge method
inspection of the disc's rear surface; refer to
Section 5 for details. Typically, the surface will
have a polished appearance, and should be
free from heavy scoring. Smooth rippling is
produced by normal operation, and does not
indicate excessive wear. Deep scoring and
cracks, however, are indications of more
serious damage in need of correction.
3 If deep scoring is discovered, it may be
possible to have the disc reground to restore
the surface, depending on the extent of the
damage. To determine whether this is a
feasible course of action, it will be necessary
to measure the thickness of the disc, as
4 Check the whole surface of the disc for
cracks, particularly around the roadwheel bolt
holes. A cracked disc must be renewed.
5 Inspect the cooling vents between the two
friction surfaces of the disc, and clear out any
traces of dirt and brake dust; blocked vents
will impair the cooling efficiency, and reduce
brake performance. Use a piece of rag
wrapped around a length of wire, soaked in
brake cleaning fluid to clear the vents. Do not
use compressed air, as this will propel the
harmful brake dust into the air.
6 A ridge of rust and brake dust at the inner
and outer edges of the disc, beyond the pad
contact area, is normal - this can be scraped
away quite easily.
7 Raised ridges caused by the brake pads
eroding the disc material, however, are an
indication of excessive wear. If close
examination reveals such ridges, the thickness
of the disc must be measured, to assess
whether it is still fit for use.
8 To measure the thickness of the disc, take
readings at several points on the surface using
a micrometer, in the area swept by the brake
pads. Include any points where the disc has
been scored; align the jaws of the micrometer
with the deepest area of scoring, to get a true
indication of the extent of the wear. Compare
these measurements with the limits listed in
Specifications. If the disc has worn below its