Page 451
Brake Calipers
523-1
523 Brake Calipers
General
Replacing Brake Calipers
(1985-1987 models)
To remove front calipers on
1985 through 1987 models
To remove rear calipers on 1985 through
1987 models
523-1
523-1
523-1
Replacing Brake Calipers
(1988 and later models)
To remove front calipers on 1988
and later models
To remove rear calipers on 1988
and later models
523-3
523-3
523-5
523-2
GENERAL
Two basic brake caliper configurations are used on cars
covered by this manual. On 1985 through 1987 cars, the front
calipers contain the parking brake assembly. On all 1988 and
later cars, the rear calipers contain the parking brake assembly. On all cars, the front calipers are bolted to the steering
swivel member while the rear calipers are bolted to the axle.
Brake fluid seeping or leaking from around the caliper piston is the result of a failed or damaged piston seal. The seal
can be replaced. However, corrosion, scoring, or pitting on the
piston will quickly destroy a new seal. It is recommended that
the caliper be replaced to remedy a leaking piston seal and to
prevent future problems.
NOTE
Always plug or cover the brake line or hose fittings whenever
the system has been opened to prevent dirt from getting into
the system. Even a minute particle of dirt can cause problems.
REPLACING BRAKE CALIPERS
(1985-1987 MODELS)
To remove front calipers on 1985 through 1987
models
1. Raise the car and support it with jackstands. Remove
the front wheels.
WARNING
• Friction materials in the brake pads may contain asbestos fibers. Avoid breathing any asbestos fibers or dust. Do not create dust by grinding or sanding, or by cleaning the pads or
disc with compressed air. Always use a respirator.
• Brake fluid is poisonous. Always wear hand and eye protection.
NOTE
• Saab recommends that the brake pad U-clips and dampers
(anti-rattle clips) be replaced whenever replacing brake pads
or calipers on 1985 through 1987 cars. The U-c1ips are prebent to help prevent brake noise (clunking noise when backing up). During normal use, the bends in the clip tend to
straighten out and the damper spring tension weakens.
• If the parking brake lever does not fully release, the lever is
sticking in the caliper or the lever retum spring is damaged.
This can lead to brake system failure and premature brake
pad wear. If the lever cannot be made to move freely, the caliper must be replaced as described below.
.;.:.;.;<.:.;.:.:.:.:.
WARNING
Make sure the car is well supported on the jackstands. Never
use just a jack to support a car.
2. Release the parking brake. Remove any rust and debris from the brake disc and caliper. Clean the hose fittings.
3. Working at the caliper, push the parking brake lever towards the sliding yoke and unhook the parking brake
cable from the lever. Remove the small circlip then pull
the cable from the sliding yoke.
4. Remove the brake pads as described in 517 Brake
Pads.
5. Pinch off the flexible hose using special brake hose
clamping pliers. Unscrew the rigid brake line fitting at
the brake hose. See Fig. 1.
REPLACING BRAKE CALIPERS (1985-1987 MODELS)
:.:-;.'.
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:111
Page 452
523-2
Brake Calipers
CAUTION
If the special hose clamping pliers are not available, remove
the brake fiuid from the fluid reseNoir using a syringe. Do not
clamp the hose using any other type of pliers. Intemal damage
to the hose may result.
brake cable as described in 517 Brake Pads. Bleed the system as described in 520 Brake Fluid and Brake Bleeding.
Adjust the parking brake cables as described in 551 Parking
Brake. Install the wheels and tighten the wheel lug nuts or
bolts. Test all brake functions for correct operation.
NOTE
NOTE
Plug the hose fittings to prevent dirt from entering the system.
The front calipers have a sliding yoke that requires cleaning
and lubrication as part of caliper replacement. Lubricate the
sliding surfaces between the caliper and yoke using Gleitmo
540 lubricant, which is available from an authorized Saab
dealer.
Tightening torques
• front caliper to
steering member
• wheel lug nuts
110 to 130 Nm (81 to 96 ft-Ib)
90 to 110 Nm (66 to 81 ft-Ib)
To remove rear calipers on 1985 through 1987
models
Fig. 3. shows an exploded view of rear caliper used on 1985
to 1987 cars.
Fig. 1. Brake line fitting being unscrewed.
6. Working from the rear of the caliper, bend the locking
plate tabs away from the caliper mounting bolt heads.
Remove the two mounting bolts. See Fig. 2.
1. Raise the car and support it with jackstands. Remove
the rear wheels.
WARNING
Make sure the car is well supported on the jackstands. Never
use just a jack to support a car.
CAUTION
Do not place a jack under the rear axle to raise up the car. The
axle may be damaged.
2. Remove any rust and debris from the brake disc and
caliper. Clean the hose fittings.
3. Remove the brake pads as described in 517 Brake
Pads.
4. Remove the rigid brake line fitting at the brake caliper.
Fig. 2. Front caliper mounting bolts (arrows). Caliper shown is
slightly different than those covered here.
NOTE
Plug the hose fittings to prevent dirt from entering the system.
Installation is the reverse of removal. Tighten the caliper
mounting bolts. Then, using a new locking plate, lock the bolts
in position by bending the tabs over the bolt heads. Do not
twist or bend the flexible brake hose when connecting the
brake line. Install the brake pads and reconnect the parking
REPLACING BRAKE CALIPERS (1985-1987 MODELS)
5. Bend the locking plate tabs away from the caliper
mounting bolt heads. Remove the two mounting bolts
holding the caliper to the axle.
Page 453
..........
Brake Calipers
1. Caliper housing
2. Piston assembly
3. Anti-rattle clip and
retaining pins
4. Brake pad (1 of 2)
5.
6.
7.
8.
Shim
Bolt locking plate
Mounting bolt (1 of 2)
Bleeder
523-3
7
6
I
I
1
B7982
1
_
Fig. 3.
Exploded view of rear calipers on 1985 to 1987 models.
Installation is the reverse of removal. Tighten the caliper
mounting bolts. Then, using a new locking plate, lock the bolts
in position by bending the tabs down over the bolt heads. Install the brake pads as described in 517 Brake Pads. Tighten
the brake hose and bleed the system as described in 520
Brake Fluid and Brake Bleeding. Install the wheels and
tighten the wheel lug nuts. Test all brake functions for correct
operation.
Tightening torques
• rear caliper to axle
• wheel lug nuts
70 to 90 Nm (52 to 66 ft-Ib)
90 to 110 Nm (66 to 81 ft-Ib)
WARNING
Make sure the car is well supported on the jackstands. Never
use just a jack to support a car.
2. Remove any rust and debris from the brake disc and
caliper. Clean the hose fittings.
3. Using special brake hose clamping pliers, pinch off the
flexible brake hose. Remove the brake line fitting to the
caliper using a brake line (flare) wrench. See Fig. 5.
WARNING
REPLACING BRAKE CALIPERS (1988
AND LATER MODELS)
If the special hose clamping pliers are not available, remove
the brake fluid from the fluid reservoir using a syringe. Do not
clamp the hose using any other type of pliers. Intemal damage
to the hose may result.
To remove front calipers on 1988 and later
models
4. Remove the bracket that holds the brake hose to the
caliper. See Fig. 6.
Fig. 4 is an exploded view of the front caliper used on 1988
and later models.
NOTE
Note how the bracket dimples fit into the caliper.
1. Raise the car and support it with jackstands. Remove
the front wheels.
REPLACING BRAKE CALIPERS (1988 AND LA TER MODELS)
Page 454
523-4
Brake Calipers
11
1.
2.
3.
4.
5.
Brake piston
Piston seal
Dust boot
Caliper housing
Brake pads
6. Guide pin boot
7. Guide pin (1 of 2 shown)
8. Caliper mounting bolt
(always replace)
9. Bleeder
Fig. 4.
Exploded view of front caliper assembly used on 1988 and
later models.
Fig. 5.
Brake line fitting being removed.
REPLACING BRAKE CALIPERS (1988 AND LATER MODELS)
10.
11.
12.
13.
Fig. 6.
Dust cap
Pad carrier
Brake hose bracket
Brake line
14. Caliper mounting bolt
(always replace)
15. Brake hose
16. Brake pad carrier
mounting bolt
Brake hose bracket being removed. Arrows show upper
and lower caliper mounting bolts.
Page 455
Brake Calipers
5. While holding the guide pins stationary, remove the upper and lower caliper mounting bolts. See Fig. 7. Remove the caliper.
523-5
spect the rubber boots for the guide pins and replace as necessary. Use new self-locking bolts when installing the caliper
to the pad carrier. Install the brake pads as described in 517
Brake Pads. Bleed the system as described in 520 Brake
Fluid and Brake Bleeding. Install the wheels and tighten the
wheel lug bolts. Test all brake functions for correct operation.
CAUTION
Always replace the front caliper mounting bolls with new ones.
These bolts are designed to be used only once and may fail
when used a second time.
Tightening torques
• caliper mounting bolt to
guide pin
30 to 35 Nm (22 to 26 ft-Ib)
• front pad carrier to steering member (1988
and later models) ..... 70 to 110 Nm (52 to 81 ft-Ib)
• wheel lug bolts. . . . . . 105 to 125 Nm (77 to 92 ft-Ib)
Fig. 7. Hold guide pins stationary using open-end wrench (A)
when loosening caliper mounting bolts (8).
6. Remove the brake pad carrier by removing the two
bolts holding it to the steering member.
Installation is the reverse of removal. Do not twist or bend
the flexible brake hose when connecting the brake line. In
To remove rear calipers on 1988 and later
models
Fig. 8. shows the rear caliper used on 1988 and later models.
1
2
9
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Guide pin cap
Boot
Guide pin (1 of 2 shown)
Bleeder
Dustcap
Piston seal
Piston seal
Dust boot
Brake pads
Brake pad carrier
11. Pad retaining clip
12. Brake caliper
13. Parking brake lever retum spring
14. Pin
15. Parking brake lever
16. Plug for piston ad
justing screw
17. Piston adjusting
screw
Fig. 8. Exploded view of rear caliper assembly used on 1988 and later models.
REPLACING BRAKE CALIPERS (1988 AND LATER MODELS)
Page 456
523-6
Brake Calipers
1. Raise the car and support it with jackstands. Remove
the rear wheel.
WARNING
NOTE
The piston caliper adjusting screw positions the piston to the
pads. The screw needs to be backed out of the caliper so that
the piston can be pushed away from the pads. More information on the piston adjusting screw is given in 517 Brake Pads.
Make sure the car is well supported on the jackstands. Never
use just a jack to support the car.
2. Unhook the parking brake cable from the caliper lever.
See Fig. 9. Pull the cable out of the caliper housing.
Fig. 11. Internal-hex head wrench (arrow) used to loosen caliper
piston adjusting screw.
Fig. 9.
Parking brake cable being unhooked from caliper,
3. Remove the pad retaining clip. See Fig. 10.
6. Using special brake hose clamping pliers, pinch off the
flexible brake hose. Loosen slightly, but do not remove,
the brake hose. See Fig. 12.
WARNING
If the special hose clamping pliers are not available, remove
the brake fluid from the fluid reservoir using a syringe. Do not
clamp the hose using any other type of pliers. Intemal damage
to the hose may result.
Fig. 10. Pad retaining clip being removed.
4. Remove any rust and debris from the brake disc and
caliper. Clean the hose fittings.
Fig. 12. Brake hose being loosened at rear caliper
5. Remove the threaded screw plug covering the piston
adjusting screw. Then unscrew the piston adjusting
screw using a 4 mm internal-hex head wrench. See
Fig. 11.
REPLACING BRAKE CALIPERS (1988 AND LATER MODELS)
Page 457
Brake Calipers
523-7
7. Remove the guide pin dust caps and then remove the
two guide pins using a 7 mm internal-hex head wrench.
See Fig. 13.
Fig. 14. Pad carrier bolts (A) and dust shield bolts (8).
Fig. 13. Lower caliper guide pin being removed. Remove upper
guide pin also.
8. Lift the caliper housing off the pad carrier and remove
the brake pads.
9. While holding the flexible brake hose stationary, unscrew the caliper. Plug the hose and caliper openings
to keep out dirt.
10. Remove the two bolts holding the pad carrier to the
axle then remove the two bolts holding the dust shield.
See Fig. 14.
Tightening torques
• rear caliper to pad
carrier (pins)
25 to 30 Nm (18 to 22 ft-Ib)
• brake pad carrier to rear axle (1988
and later models)
40 to 54 Nm (30 to 40 ft-Ib)
• wheel lug bolts
105 to 125 Nm (77 to 92 ft-Ib)
• all other fasteners
M5 bolt
5 Nm (44 in-Ib)
M6 bolt .. "
10 Nm (89 in-Ib)
M8 bolt
20 Nm (15 ft-Ib)
M10 bolt
40 Nm (30 ft-Ib)
Installation is the reverse of removal. Reinstall the brake
pads and adjust the piston as described in 517 Brake Pads.
Tighten the hose and bleed the system as described in 520
Brake Fluid and Brake Bleeding. Reconnect the parking
brake cable and check the cable adjustment as described in
551 Parking Brake. Install the wheels and tighten the wheel
lug bolts. Test all brake functions for correct operation.
REPLACING BRAKE CALIPERS (1988 AND LATER MODELS)
Page 458
Brake Pedal Mechanism
524-1
524 Brake Pedal Mechanism
General
To remove brake pedal.
524-1
524-1
GENERAL
The brake pedal mechanism consists of the brake pedal
and connecting linkage that transmits the mechanical force
from the driver's foot to the master cylinder. The mechanism is
located next to the steering column in the passenger compartment. See Fig. 1.
2. Working at the brake pedal assembly, remove the padded insulating material then remove the defroster hose
from the heater box.
3. Unhook the brake pedal return spring. See Fig. 2.
WARNING
On cars equipped with an SRS airbag system, do not attempt
to service the wiring in the steering wheel, steering column assembly, or airbag control unit without first disarming the SRS
system. The airbag may ignite causing injury. See an authorized Saab dealer for any repairs necessary to the SRS wiring
or components.
To remove brake pedal
1. Remove the lower dashboard pad and footwell heating
duct as described in 851 Interior Trim and Upholstery.
Fig. 2. Brake pedal return spring (arrow).
8
1.
2.
3.
4.
5.
6.
7.
8.
9.
Brake pedal
Pedal spindle bolt
Retum spring
Locking clip (cotter pin
used on 1985 models,
not shown)
Push rod clevis pin
Bushing
Spacer tube
Self-locking nuts
(always replace)
Bracket
Fig. 1. Exploded view of brake pedal assembly.
GENERAL
Page 459
524-2
Brake Pedal Mechanism
4. Remove the locking clip (or cotter pin) and the pushrod
pin for the master cylinder pushrod. See Fig. 3.
7. Remove the brake pedal. It may be necessary to rotate
the pedal as it is being removed. Be sure to save the
bushings and spacer tube. See Fig. 4.
NOTE
Inspect the bushings and spacer tube for any signs of wear
and replace as necessary.
Fig. 3.
Locking clip (arrow) for pushrod pin on master cylinder.
1985 models use a cotter pin instead of a locking clip.
.
NOTE
Note the orientation of the push rod pin and locking clip (or cotter pin).
5. Remove the mounting plate for the brake light switch.
6. Remove the self-locking nut for the pedal spindle bolt.
Remove the bolt.
WARNING
Always replace the self-locking nut with a new one. Self-locking nuts are designed to be used only once and may loosen
and fall off when used a second time.
Fig. 4. Brake pedal being removed.
Installation is the reverse of removal. Always replace selflocking nuts with new ones. On 1985 models, use a new cotter
pin. Adjust the brake light switch as described in 364 Electric
Controls and Switches.
CAUTION
Inspect the push rod locking clip and replace it with a new one
if it is in anyway damaged or defonned.
Test all braking functions and check that the brake lights are
working. Where applicable, test cruise control functions.
GENERAL
Page 460
Brake Vacuum Booster
541-1
541 Brake Vacuum Booster
General
541-1
Replacing Vacuum Booster
541-1
541-1
To remove vacuum booster unit
GENERAL
The vacuum booster is used to assist braking by reducing
the effort required of the driver to operate the master cylinder.
Engine manifold vacuum, ported to the booster, acts on a diaphragm to boost the driver's own force on the master cylinder.
See Fig. 1. The vacuum booster is a sealed unit and cannot be
repaired.
NOTE
A vacuum booster is not used on cars with ASS. Instead, the
brake assist is handled through the ASS unit. See 500
Brakes-General for more information on the ASS system.
A quick-check of the vacuum booster can be made by
pumping the brake pedal approximately 10 times with the engine off. Then while holding the pedal down, start the engine.
the pedal should fall slightly. If not, the booster may be faulty.
NOTE
For a more accurate check of the vacuum booster and check
valve, create a vacuum in the booster using a hand-held vacuum pump. Apply vacuum at the vacuum hose from the intake
manifold. The system should not leak. See Fig. 2.
\,
;
I
B7990·S5/088
Fig. 2. Vacuum booster unit and check valve (A). Apply vacuum at
hose (arrow) to test unit.
Replacing the vacuum booster involves disconnecting the
push rod linkage at the brake pedal and removing the brake
master cylinder first.
To remove vacuum booster unit
1. Disconnect the battery negative (-) cable.
Fig. 1. Vacuum booster unit.
REPLACING VACUUM BOOSTER
The vacuum booster should be replaced if braking pedal effort is too high from a fault with the vacuum booster. If the
booster is unable to hold vacuum after the engine is stopped,
the vacuum check valve and seal may be defective or there
may be a leak in the seal between the vacuum booster and the
master cylinder.
2. Remove the lower dashboard pad and footwell heating
duct as described in 851 Interior Trim and Upholstery.
WARNING
On cars equipped with an SRS airbag system, do not attempt
to service the wiring in the steering wheel, steering column assembly, or airbag control unit without first disarming the SRS
system. The airbag may ignite causing injury. See an authorized Saab dealer for any repairs necessary to the SRS wiring
or components.
REPLACING VACUUM BOOSTER