SAAB 9000. Instruction - page 41
9•14 Braking system
8 Remove the terminal blocks from the
battery tray. Unbolt the battery tray from the
inner wing, and lift it out of the engine bay.
9 Refer to Chapter 1 and drain the brake fluid
from the system.
10 Refer to Section 10 and remove the
master cylinder.
11 Refer to Section 11 and extract the non-
return valve from the vacuum servo unit, but
leave it connected to the vacuum hose leading
to the inlet manifold.
12 Working in the cabin, from the left-hand
side footwell, remove the four servo unit
retaining nuts, located behind the brake
linkage bracket.
Caution: Get an assistant to
support the servo unit as you do
this, to prevent it from dropping
out as the last nut is removed.
Refitting
13 Clean the mating surfaces of the servo unit
and the bulkhead. Fit a new gasket over the
servo mounting studs.
14 Offer up the servo unit to its mounting
location. Insert the link rod through the
bulkhead, ensuring that it aligns correctly with
the brake linkage.
15 Refit the clevis pin and retaining clip. Refit
the four retaining nuts to the servo unit studs
protruding through the bulkhead, and tighten
them to the correct torque. Press the trim back
into place behind the pedals.
16 Reconnect the vacuum hose by pressing
the non-return valve back into the grommet on
the servo unit; refer to Section 11 for details.
17 Refit the master cylinder, brake lines and
hoses, referring to Section 10 for guidance.
18 Refit the battery tray, battery and battery
cables by reversing their removal sequence.
Reconnect the terminal blocks to the battery
tray.
19 On pre-1990 model year vehicles, refit the
fuel filter and its retaining strap.
20 Fill the brake fluid reservoir to the "MAX"
mark and bleed the entire brake system; refer
to Section 2 for a detailed description of this
operation.
21 Test the operation of the servo unit, as
described at the beginning of this Section,
before bringing the vehicle back into service.
Warning: Adjustment of the
handbrake should be carried out
after the brake discs have been
allowed to cool completely, and
not immediately after driving the vehicle,
when the discs may still be hot. The
expansion of the discs at high
temperatures may give rise to an
inaccurate adjustment
1 If the handbrake has to be pulled through an
excessive degree of travel before it takes
effect, or if the rear wheels appear to be
binding, the handbrake may be in need of
adjustment (see illustration).
2 Park the vehicle on a level surface, with the
engine and ignition switched off. Select first
gear (manual transmission) or "Park" (automatic
transmission). Do not apply the handbrake.
3 Chock the front wheels, raise the rear of the
vehicle and rest it securely on axle stands -
refer to "Jacking, towing and wheel changing"
for guidance.
4 Remove both rear roadwheels to gain
access to the brake calipers.
5 Remove the retaining screw and prise the
brush seal out of the centre console, and slide
it off the handbrake lever. This will expose two
adjusting nuts, at the base of the lever; remove
the plastic lockplate from them, and put it to
one side (see illustration).
6 At the right-hand rear caliper, unscrew the
plug from the adjusting screw hole. Use a
4 mm Allen key to turrrthe adjusting screw
clockwise until it reaches the end of its travel,
then back it off half a turn. This should set the
brake pads just clear of the disc - rotate the
disc by hand, and check that it still turns
freely. If it binds, back off the adjusting screw
by a further quarter-turn and check the disc
again. Refit the adjusting screw plug.
7 At the caliper, slide a 1.0 mm feeler blade
between the handbrake actuator lever and its
end stop. Inside the car, turn the right-hand
adjusting nut at the base of the handbrake
lever to decrease or increase the clearance at
the caliper. The clearance is set correctly
when the feeler blade will just slide between
the lever and end stop, with slight resistance
(see illustration).
8 If the correct clearance cannot be obtained,
or if it can be set correctly but the brake disc
still binds on the pads, after the handbrake is
applied and released, check the handbrake
actuator lever and return spring on the caliper
for signs of corrosion or damage. If no
problems exist there, the handbrake cables
may be sticking internally due to corrosion -
refer to Section 14 for more information.
13.5 Removing the plastic lockplate, to
expose the handbrake cable adjusting nuts
13.1 Handbrake cable layout and adjustment mechanism
1 Cover 3 Cable 5 Plastic locking plate 7 Handbrake lever
2 Cable guide 4 Pivot pin 6 Adjusting nuts 8 Pawl release button
13.7 At the caliper, slide a 1.0 mm feeler
blade between the handbrake actuator
lever and its end stop
Braking system 9•15
9 Repeat the above procedure at the left-
hand caliper, this time using the left-hand
adjusting screw at the handbrake lever to set
the clearance.
10 Upon completion, press the lockplate over
the adjusting screws at the base of the
handbrake lever.
11 Slide the brush seal over the handbrake
lever, and refit it to the centre console. Secure
the brush seal by refitting its retaining screw.
12 Refit the roadwheels, and after lowering the
vehicle to the ground, tighten the wheel bolts.
13 Before bringing the vehicle back into
service, thoroughly check the operation of the
handbrake.
Note: On post-1988 model year vehicles, the
fuel tank must be lowered away from its
mountings slightly, to allow the handbrake
cables to be withdrawn; refer to Chapter 4 for
details.
Removal
1 Park the vehicle on a level surface, with the
engine and ignition switched off. Select first
gear (manual transmission) or "Park"
(automatic transmission). Do not apply the
handbrake.
2 Refer to Chapter 11 and remove the front
left-hand seat.
3 Prise the brush seal out of the centre
console, and slide it off the handbrake lever.
Unscrew the bezel, and slide the gaiter off the
gear change/selector lever. Remove the four
retaining screws, and lift off the rear section of
the centre console. Refer to Chapter 11 for
more detail.
4 Remove the sill anti-scuff plates, after
extracting the retaining screws.
5 Fold back the carpet to expose the cable
channel, and unscrew the cover.
6 Remove the lockplate from the handbrake
cable adjusting nuts, and put it to one side;
refer to Section 13 for details.
7 Fully slacken both the adjusting screws,
detaching them from the bracket on the
handbrake lever and the handbrake cables.
8 Chock the front wheels, raise the rear of the
vehicle and rest it securely on axle stands -
refer to "Jacking, towing and wheel changing"
for guidance.
9 Remove both rear roadwheels to gain
access to the brake calipers.
10 At the first caliper, unhook the handbrake
cable from the actuator lever, and recover the
rubber gaiter; refer to Section 4.
11 Unscrew/prise out the cable guide from
the suspension lower arm, as applicable.
12 Free the remainder of the cable by pulling
it through the grommet in the floorpan - the
cable assembly can now be withdrawn from
the vehicle.
13 Repeat the above procedure for the
remaining cable.
Refitting
14 Guide the end of the first new cable
through the grommet in the floorpan.
15 Screw/press the other end of the cable
into the spring guide on the suspension lower
arm, as applicable
16 From inside the car, pull the cable through
to the bracket on the base of the handbrake
lever. Thread the adjusting screw onto the end
of the cable, but do not tighten it fully.
17 Working at the caliper, pack the rubber
gaiter with grease, and thread the handbrake
cable inner through it. Hook the cable outer
into the slotted bracket affixed to the caliper,
and engage the inner cable nipple with the
handbrake actuator lever.
18 Repeat the above the procedure to fit the
second cable.
19 On post-1988 model year vehicles, raise
the fuel tank back into place and secure the
mountings; refer to Chapter 4 for details.
20 Apply and release the handbrake several
times, to allow the cables to stretch and settle.
21 Refer to Section 13 and adjust the
operation the handbrake.
22 Refit the roadwheels, then lower the
vehicle to the ground and tighten the wheel
bolts to the specified torque.
23 Screw down the cable covers inside the
car, and lay the carpet back in position. Refit
the sill anti-scuff plates.
24 Refer to Chapter 11 and refit the centre
console, handbrake lever brush seal, and the
seat.
25 Perform a full check of the handbrake
operation, as described in Section 13, before
bringing the vehicle back into service.
Removal
1 Park the vehicle on a level surface, with the
engine and ignition switched off. Select first
gear (manual transmission) or "Park"
(automatic transmission). Do not apply the
handbrake.
2 Prise the brush seal out of the centre
console, and slide it off the handbrake lever.
Unclip the bezel, and slide the gaiter off the
gear change/selector lever. Remove the four
retaining screws, and lift off the rear section of
the centre console; refer to Chapter 11 for
more detail.
3 Prise the lockplate off the two handbrake
cable adjusting nuts, and retain it for refitting
later. Slacken and remove the adjusting nuts,
then free the two cables from the brackets on
the sides of the handbrake lever.
4 Remove the circlip from the end of the
handbrake lever pivot pin, then draw the pin
out.
5 Lift the handbrake lever away from its
mounting bracket.
Refitting
6 Refit the lever to its mounting bracket, then
push the pivot pin through, engaging it with
the mounting bracket / ratchet plate.
7 Guide the handbrake cables through the
brackets on the side of the lever, and refit the
adjusting nuts.
8 Refer to Section 13, and adjust the
operation of the handbrake. Remember to fit
the adjusting nut lockplate upon completion.
9 Refit the centre console, handbrake lever
brush seal and gear change/selector lever
gaiter by reversing the removal procedure -
refer to Chapter 11 for guidance.
Removal
1 The handbrake "ON" warning light switch is
mounted on a bracket bolted to the floorpan,
directly underneath the handbrake lever. Refer
to Chapter 11 and remove the rear section of
the centre console to expose it.
2 Park the vehicle on a level surface, and
apply the handbrake.
3 Remove the bolt securing the mounting
bracket to the floorpan, and unplug the switch
at the cable connector. Lift the assembly out
of the vehicle.
Testing
4 The switch is a single-pole device, and has
normally-closed (NC) contacts. The operation
of the switch can be tested using either a
multimeter (switched to the resistance
measurement function), or a continuity tester
made up of a flashlight bulb, dry cell battery
and two pieces of wire. Connect the
meter/tester to the switch connector terminals
(the order of connection is immaterial) with the
switch in its rest position. A healthy switch will
show a short-circuit reading (no more than
1 or 2 ohms) on the meter, and will light the
continuity tester light.
5 Press the switch plunger down, and repeat g
the measurement. The reading on the meter
should be open-circuit (very high resistance),
and the continuity tester light should go out.
6 If the switch does not behave as described,
or is intermittent in its operation, then it must
be replaced; the unit is not serviceable.
Refitting
7 Bolt the switch mounting bracket to the
floorpan, and plug in the cable connector.
8 Ensure that the vehicle is parked on a level
surface. Select first gear (manual transmission)
or "Park" (automatic transmission), apply the
footbrake and switch on the ignition - but do
not start the engine.
9 Release the handbrake, and check that in its
rest position, the metal tab protruding from the
handbrake lever contacts the switch plunger
squarely and pushes it down. The handbrake
9•16 Braking system
"ON" warning light on the dashboard should
go out.
10 Reapply the handbrake, and check that
the metal tab now clears the switch plunger,
allowing it to extend fully. The handbrake "ON"
warning light on the dashboard should now be
lit.
11 Refer to Chapter 11 and refit the rear
section of the centre console.
General information
1 The vehicle's braking system is laid out
principally to serve the left-hand drive market.
In this configuration, the brake pedal acts
directly on the master cylinder via a single
pushrod linkage. Right-hand drive vehicles are
fitted with a mechanism that transfers effort
from the brake pedal across the bulkhead, to a
bracket directly behind the master cylinder/
vacuum servo/ABS hydraulic unit on the left of
the vehicle.
Removal
2 Park the vehicle on a level surface, and
apply the handbrake. Working in the right-
hand footwell, remove the soundproofing
panel from the underside of the dashboard, to
expose the pedal assemblies. Refer to
Chapter 11 for guidance in removing trim
panel fixings without damaging them.
3 Where applicable, refer to Chapter 4A and
remove the cruise control cancel switches.
4 Remove the retaining clip, and extract the
clevis pin from the point where the pedal is
joined to the servo unit pushrod.
5 Refer to Chapter 6 and remove the clutch
pedal (vehicles with manual transmission
only).
6 Note the position of the brake pedal return
spring - push the hooked ends off the bracket,
and allow the brake pedal to drop out of the
bracket. Recover the plastic bushes.
7 Extract the two smaller plastic bushes and
the metal pivot pin bush from the pedal - note
their order of assembly.
Refitting
8 Refit the components by reversing the
removal process. For vehicles fitted with
manual transmission, refer to Chapter 6 for
details of refitting the clutch pedal.
correctly, the stop-lights should come on
after the brake pedal has been depressed
by 10 mm.
2 Working from the left-hand footwell, remove
the sound insulation panel from underneath
the facia; refer to Chapter 11 for details.
3 Ensure that the ignition switch is turned to
the "off" position, then unplug the electrical
cables from the switch terminals.
4 At the end of the stop-light switch body,
squeeze together the plastic tangs, and pull
the switch back through the mounting bracket.
Testing
5 The switch is a single-pole device, and has
normally-closed (NC) contacts. The operation
of the switch can be tested using either a
multimeter (switched to the resistance
measurement function), or a continuity tester
made up of a flashlight bulb, dry cell battery
and two pieces of wire. Connect the
meter/tester to the switch connector terminals
(the order of connection is immaterial) with the
switch in its rest position. A healthy switch will
show a short-circuit reading (no more than
1 or 2 ohms) on the meter, and will light the
continuity tester light.
6 Press the switch plunger down, and repeat
the measurement. The reading on the meter
should be open-circuit (very high resistance),
and the continuity tester light should go out.
7 If the switch does not behave as described,
or is intermittent in its operation, then a new
switch must be fitted; the unit is not
serviceable.
Refitting
8 Refit the brake light switch by reversing the
removal procedure.
The Anti-lock Braking System (ABS) is
managed by an Electronic Control Unit (ECU),
which has the capacity to monitor the status
and condition of all the components in the
system, including itself. If the ECU detects a
fault, it responds by shutting down the ABS
and illuminating the dashboard-mounted ABS
warning light. Under these circumstances,
conventional non-ABS braking is maintained.
If the nature of the fault detected is such that it
may interfere with the operation of the
conventional braking system as well, the ECU
also illuminates the normal brake warning
light.
As a consequence, if the ABS warning lights
indicate that all is not well, it is very difficult to
diagnose problems with the system, without
the equipment and expertise to electronically
"interrogate" the ECU. Hence, this Section is
limited firstly to a list of the basic checks that
should be carried out, to establish the integrity
of the system, (eg - is there enough brake
fluid?, is anything leaking?, etc). Section 20 is
limited to a description of the removal and
refitting of the ABS wheel sensors and ECU
only, as in certain instances, it will be
necessary to remove these components to
gain access to other assemblies on the
vehicle.
If the cause of the fault cannot be
immediately identified using the check list
described, the only course of action open is to
take the vehicle to a Saab dealer for
examination. Dedicated test equipment is
needed to interrogate ABS ECU, to determine
the nature and incidence of the fault. For
safety reasons, owners are strongly advised
against attempting to diagnose complex
problems with the ABS using standard
workshop equipment.
Basic fault-finding checks
Brake fluid level
1 Check the brake fluid level with the vehicle
parked on a flat surface, and the accumulator
fully charged. To ensure that the accumulator
is fully charged, switch on the ignition and
listen to the hydraulic pump, which is part of
the hydraulic unit assembly. The sound made
by the pump will be quite audible; when it
stops, the accumulator will be fully charged.
Switch off the ignition, and without touching
the brake pedal, check the brake fluid level in
the reservoir. If necessary, top it up to the
"MAX" mark with brake fluid of the correct
grade.
2 If the level is exceptionally low, there may be
leak somewhere in the hydraulic system. Refer
to Chapter 1 and carry out a check of the brake
hoses and pipes throughout the vehicle. If no
leaks are apparent, remove each roadwheel in
turn, and check for leaks at the brake caliper
pistons - refer to Sections 5 and 6 for details of
the front and rear caliper layout.
Fuses and relays
3 The fuses (and relays) for the ABS are
situated in a separate protective box, in the
engine bay adjacent to the brake fluid
reservoir (see illustration). Remove the cover
and pull out each fuse, one by one. Visually
check the fuse filament; if it is difficult to see
19.3 ABS fuses and relays
1 Hydraulic pump motor relay
2 ECU relay
3 ECU fuse, 10A
4 ECU fuse, 3OA
5 Hydraulic pump motor fuse, 3OA
Removal
1 On right-hand drive vehicles, the stop-light
switch is mounted on the brake linkage
bracket, on the bulkhead at the left-hand side
of the vehicle; refer to Section 17, General
Information. It is a single-pole switch, whose
contacts are normally closed. When operating
Braking system 9•17
whether or not it has blown, use a multimeter
or continuity tester to check the electrical
continuity of the fuse. If any of the fuses are
blown, do not fit a new one, until the fault that
caused the fuse to blow has been found and
rectified; have the vehicle inspected by a Saab
dealer, and inform him of your findings.
Caution: Fuses are there to
protect equipment and people
from damage; a blown fuse is an
indication of a problem. Simply
fitting a new fuse, or even bypassing the
old one before the problem is corrected,
will increase the risk of damage, and may
result in a fire.
4 The system relays can be found in the same
protective box as the fuses. In general, relays
are difficult to test conclusively without an
electrical specification. However, the metal
contacts inside a relay can usually be felt (and
often heard) to open or close as it operates - if
the relay in question does behave in this way
when the ignition switch is turned on, it may
be faulty. It should be noted that this is not a
conclusive test; substitution with a known
good relay of the same type is the only way to
verify the component operation. If any of the
relays is suspected of being faulty, it can be
renewed by pulling it out of its socket - noting
its orientation - and pushing in a new unit.
Electrical connections and earthing
points
5 The engine bay is a hostile environment for
electrical connections, and even the best seals
can sometimes be penetrated. Water,
chemicals and air will induce corrosion on the
connector's contacts and prevent good
continuity, sometimes intermittently.
Disconnect the battery negative cable, then
check the security and condition of all
connectors at the ABS hydraulic unit, situated
in the engine bay on the rear bulkhead. Unplug
each connector, and examine the contacts
inside.
6 Clean contacts that are found to be dirty or
corroded using a proprietary contact cleaning
oil, obtainable in most garages and car
accessory shops. Avoid scraping the contacts
clean with a blade, as this will accelerate
corrosion later. Use a piece of lint-free cloth in
conjunction with the cleaning oil to produce a
clean, shiny contact surface that will result in
good electrical continuity.
7 In addition, check the security and condition
of the electrical earthing point, on the front of
the hydraulic unit.
1 Due to the complexity of the ABS, and the
fact that specialised test equipment is needed
to diagnose faults with it, this Section is limited
to a description of the removal and refitting of
the ABS wheel sensors and ECU only, as in
certain instances, it will be necessary to
remove these components to gain access to
other assemblies on the vehicle. Section 19
contains a list of the basic checks that should
be carried out, to establish the integrity of the
ABS system, and to help identify any
prominent faults.
Wheel sensors
General
2 Two different types of ABS wheel sensor
have been fitted to the Saab 9000 to date,
although both versions are very similar in
appearance and operation.
3 The most significant difference between the
types of sensor is the method of installation
and adjustment. Sensors fitted to pre-1990
model year vehicles have two fixings built into
the sensor housing; a bolt to secure the
sensor to the wheel hub assembly, and a set
screw to adjust the protrusion depth of the
sensor tip. The set screw has been deleted
from sensors fitted to post-1990 model year
vehicles, as these have a fixed protrusion
depth, and require no adjustment once
installed.
4 The later type of sensor can be retro-fitted
to pre-1990 model year vehicles, by
transferring the set screw and adjustment
sleeve from the old sensor to the new one. A
self-adhesive fibre spacer 0.65 mm thick
(available from Saab dealers) is then pressed
onto the end of the sensor tip, to give the
20.12a Slacken and withdraw the sensor
retaining bolt...
20.12b ... and remove the sensor from the
hub assembly, together with its protective
sleeve
correct clearance when it is fitted; this
procedure is described in more detail later in
this Section.
Front wheel sensors - removal
5 Locate the harness connectors in the engine
bay, behind the false bulkhead panel. They are
bayonet-type connectors, released by
squeezing together the^ finger grips and
twisting the two halves of the connector apart.
6 Where applicable, raise the air conditioning
coolant pipe clips by slackening the pipe clips,
to allow the connector to pass underneath.
7 Slacken the retaining bolts, and raise the
false bulkhead panel to allow the sensor cable
and connector to pass underneath.
8 Ensure that the vehicle is parked on a level
surface, then apply the handbrake and chock
the rear wheels. Raise the front of the vehicle,
resting it securely on axle stands, and remove
the front roadwheel(s). Refer to "Jacking,
towing and wheel changing" for guidance.
9 Refer to Chapter 11, and remove the rear
section of the inner wheelarch liners.
10 Use a pair of cable shears to cut through
the cable-tie that secures the sensor cable to
its mounting bracket.
11 Carefully guide the sensor cable and
connector through the grommet in the
wheelarch.
12 Slacken and withdraw the sensor retaining
bolt, extract the cable from the bracket at the
base of the strut mounting, and remove the
sensor from the hub assembly, together with
its protective sleeve (see illustrations).
Front wheel sensors - refitting
13 Push the sensor into the drilling in the hub
assembly, then refit and tighten the retaining
bolt.
14 Using a feeler blade inserted between the
sensor tip and the toothed disc, set the
clearance to the value listed in Specifications.
When the clearance is correct, tighten the set
screw.
15 Pass the sensor connector and cable
through the grommet in the wheelarch, then
secure the cable to the mounting bracket on
the suspension strut, using a new cable-tie.
16 Refit the remainder of the components by
reversing the removal sequence.
Rear wheel sensors - removal
17 Tilt the rear seat forwards to expose the
cable covers in the floorpan. Remove the right
or left-hand cover, as applicable.
18 Unplug the sensor cable at the connector.
Note that the connectors are of the bayonet
type, released by squeezing together the
finger grips and twisting the two halves of the
connector apart.
19 Ensure that the vehicle is parked on a level
surface, then chock the front wheels and
select first gear (manual transmission) or
"Park" (automatic transmission). Raise the rear
of the vehicle, rest it securely on axle stands
and remove the right or left-hand rear
roadwheel, as appropriate. Refer to "Jacking,
towing and wheel changing" for guidance.