Page 451
MASTER CYLINDER
off the locking nut and unscrew the push rod from
. the fork on the brake pedal.
to and incl. model ini
Up 1968 3. Back off and remove the two master cylinder retaining
bolts. The lower one is a stud bolt and the nut is acces-
GENERAL 1
sible from the engine compartment. The upper one Is
a screwbolt, accessible from inside the car.
All work on the brake system must be done under condi- 4. Remove the master cylinder
tions of scrupulous cleanliness and carefulness. See sec-
tion 520.
DISMANTLING
REMOVAL
: The master cylinder should only be dismantled if there is
1. Disconnect the connections for outlet brake lines from no exchange system for this unit.
the master cylinder. 1, Remove the rubber bellows (11) together with retain-
2. Remove the rubber boot from the push rod, or back ing plate (8) and the push rod (31).
WOVet
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19 2122 s 710
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MASTER CYLINDER, SECTIONED, UP TO AND INCL, MODEL 1968
A = 0.024—0.047 in. (0.6—1.2 mm)
1, Outlet to the secondary circuit 12, Primary cup 22. Piston washer
2. Outlet to the primary circuit 13, Piston washer 23. Piston stop
3. By-pass port 14. Secondary piston 24. Circlip
4. Feed hole 15. Secondary cup 25. Washer
5. Brake fluid reservoir 16. Body 26. Secondary cup
6. By-pass port 17. Clip 27. Guide bearing
7. Feed hole 18. Spring 28. Circlip
8. Retaining plate 19. Retaining pin 29. "'Spirolox” circlip
9. Spring 20. Spring holder 30. Spring retainer
10. Primary piston 21. Primary cup 31. Push rod
11. Rubber boot
Febr 1977
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Page 452
3. Remove the outer lock r
2. Press down the spring retainer (30
) and remove th
spiral clip (29) with the seh
aid of a small screwdriver,
ing (28), the nylon bearin
(27), the cup (26), and the Washer (25). ,
4.R i i
emove the inner lock ring (24) with the aid of special
tool 78 41 992 and remove the pistons.
REMOVING THE LOCK RING
Tool 78 41 992
NOTE
Be careful when removing the locking ring and the
washer so that the surface of the pistons not be dam-
aged.
. Compress the intermediate spring (18) together with
spring holder (20) and drive out the retaining pin (19),
using a suitable pin punch. This will separate the two
pistons (10 and 14), and allows the withdrawal of the
spring (18) and spring holder (20).
NOTE! It is not possible to remove the clip (17) on
the secondary piston.
_ Withdraw the non-return valves. Take care not to dis-
tort the spring clip (44) when removing it from the
valve body.
521-2
—
NON-RETURN VALVE IN MASTER CYLINDER
41. Spring
42. Valve body
43. Equalizing hole
44, Spring clip
45. Gasket
46. Adapter
7. Remove the six bolts retaining the cover of the brake
fluid reservoir (5) and take off the cover together with
the gasket.
8. Put the parts in a vessel containing brake fluid for
cleaning. Methylated spirit can be used for cleaning
but the parts must then be wiped thoroughly dry.
INSPECTION
1. Check that the cylinder bore is not scored.
2. Check that the by-pass holes are clean by probing with
a piece of thin steel wire.
3. Check all parts, and renew any defective ones. Inter-
nal rubber parts should be replaced by new ones, which
are available in suitable kits.
Febr 1977
Page 453
REASSEMBLY
Before reassembling the master cylinder, dip all parts in
brake fluid.
1. Locate the cups on the pistons and check that they
are correctly positioned, see fig.
=
nu,
aon---—Pp
—
FITTING THE PISTON WASHER
12. Primary cup
13. Piston washer (dished)
14. Secondary piston
2. Install the spring (18) on the pistons and press them
together so that the retaining pin (19) can be installed.
3. Fit the pistons in the cylinder. NOTE! Be carefull so
that the gaskets not be damaged.
4. Install the piston stop (23).
5. Mount spiral clip (24) with the aid of tool
78 41 992.
6. Install the washer (25), the secondary cup (26) and
the nylon bearing (27). Lock with spiral clip (28).
7. Install spring (9) and spring retainer (30) on the pri-
mary piston (10).
8. Compress the retain spring (9) and install the spiral
clip (29).
9. Lubricate the small end of the push rod (31) with
silicon grease and install the rubber bellows (11) with
retainer (8).
10. Screw on the outlet adapters and non return valves.
Tighten to 38 Nm (28 ft.-lb., 3.8 kpm).
11. Install the cover 5 and tighten the screws to 7 Nm
(6 ft.-Ib., 0.7 kpm).
INSTALLATION
1. Cover all openings to prevent the entry of foreign mat-
ter into the cylinder during the installation work.
2. Attach the brake cylinder.
3. Refit the rubber boot to the push rod. Reassemble the
push rod if it has been disassembled.
4. Reconnect the outlet brake lines and refill the system
with brake fluid.
5. Adjust the brake pedal free movement. See section
524,
6. Bleed the system. See section 520.
Febr 1977
As from model 1969
If it is necessary to dismantle the brake system, or any
part thereof, this must be done under conditions of scru-
pulous cleanliness, See section 520.
REMOVAL AND INSTALLATION OF MASTER CYL-
INDER WITH VACUUM SERVO
1. Remove the protective cover of the steering wheel
shaft.
2. Loosen the screw joints of the outlet brake lines at
the master cylinder. Disconnect the vacuum hose
from the vacuum servo.
3. Detach the push rod at the brake pedal.
4. Loosen the four nuts retaining the vacuum servo to
the dash panel. The nuts are accessible from inside
the car. Remove the master cylinder.
The installation is made in the reverse order.
REMOVAL AND INSTALLATION OF MASTER CYL-
INDER
When removing and installing the master cylinder, it is
not necessary to remove the vacuum servo.
1. Loosen the screw joints of the outlet brake lines at
the master cylinder.
2. Remove the two nuts retaining the master cylinder
to the vacuum servo.
3. Remove the master cylinder.
The installation is made in the reverse order.
Bleeding the brake system, see section 520.
521-3
Page 454
Model 1969—1970
DISMANTLING
The master cylinder should only be dismantled if there is
no exchange system for this unit.
521—4
1. Depress the spring retainer (30) and, using a small
screwdriver, unwind the spiral clip (29) from the
groove of the primary piston, taking care not to
distort the coils; remove the spring retainer (30) to-
gether with the spring (8). Remove the washer (28)
and the gasket (27).
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MASTER CYLINDER, SECTIONED, MODEL 1969-1970
1. Outlet to the secondary circuit
2. Outlet to the primary circuit
3. By-pass port
4. Feed hole
5. Brake fluid reservoir
6. By-pass port
7. Feed hole
8. Spring
9. Primary piston
10. Primary cup
11. Piston washer
12. Secondary piston
13. Secondary cup
14, Body
15, Wire cip
16. Spring
17, Retaining pin
18. Spring holder
19. Primary cup
20. Piston washer
21. Piston stop ring
22. Circlip
23. Washer
24. Secondary cup
25. Guide bearing
26. Circlip
27. Gasket
28. Washer
29. “Spirolox” circlip
30. Spring retainer
Febr 1977
:
Page 455
2. Remove the circlip (26), taking great care not to
damage the surface finish of the primary piston (9), | * 35
Lightly tap the mounting flange of the cylinder oan fame
body on the bench, and remove the nylon guide R /
bearing (25), the secondary cup (24) and the plain
washer (23). BN
3. Using special circlip pliers with long, narrow jaws, | g
tool 78 41 992 remove the inner circlip (22), again iT Spee :
taking great care not to damage the surface finish
of the primary piston (9),
bnieoe
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FITTING THE PISTON WASHER
10, Primary cup
11. Piston washer (dished)
12, Secondary piston
9. Remove the 4 bolts retaining the cover of the
brake fluid reservoir (5) and take off the cover to-
gether with the gasket.
10. Clean the parts in brake fluid or methylated spirit.
570
REMOVING THE LOCK RING
Too! 78 41 992
INSPECTION
_
. Check that the cylinder bore is not scored.
4. Removal of the circlip will allow the withdrawal of 2. Check that the by-pass holes are clean by probing with
both pistons together with the piston stop (21). a piece of thin steel wire.
5. Compress the intermediate spring (16) together 3. Check all parts, and renew any defective ones. Internal
with spring holder (18) and drive out the retaining rubber parts should be replaced by new ones.
pin (17), using a suitable pin punch. This will sepa-
rate the two pistons (9 and 12), and allows the
withdrawl of the spring (16) and spring holder (18).
6. Remove the primary cups (10 and 19) together REASSEMBLY
with the piston washers (11 and 20) from the pri-
mary and secondary pistons. Remove the secondary Before reassembling the master cylinder, dip all parts in
cup (13) from the back of the secondary piston. brake fluid.
Do not attempt to move the clip (15) from the se- 1. Using the fingers only, stretch the secondary cup
condary piston, as this part is permanently peened (13) over the large end of the secondary piston
in position. with the lip pointing towards the peened clip.
7. Unscrew the outlet adapters (31) and remove them Gently work round the cup with the fingers to en-
together with the gaskets. sure correct bedding.
8. Withdraw the non-return valves, comprising the 2. Locate the piston washer on the secondary piston
spring (32), valve body (33) and spring clip (34). spigot. Using the fingers only, ease the primary cup
Take care not to distort the spring clip (34) when (10) over the nose of the spigot and into the groove,
removing it from the valve body. ee ee the cup pointing away from the head
Febr 1977 SAAB 521-5
Page 456
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NON-RETURN VALVE
31, Outiet screw joint
32. Spring
SX. Valve body
SM. Valve spring
SS. Gasket
3. Adopt the same procedure with the primary cup
(19) and piston washer (20) of the primary piston.
Ease the spring holder (18) into the end of the
spring (16) and fit the other end of the spring over
the rear of the secondary piston (12).
4. Locate the retaining pin (17) in the hole in the pri-
mary piston, but do not push fully home. Compress
the spring until the secondary piston clip (15) is vis-
ible. Place the clip in position in the primary piston
and secure it by pushing the retaining pin fully
home. Release the spring and check that the spring
holder (18) is correctly positioned.
521-6
10,
V1,
Ease the pistons gently into the cylinder bore and
stide the piston stop (21) over the primary piston
Fit the cirelip (22) in the inner groove, Using specia!
ciretip pliers with long, narrow jaws, tool 78 41 90°
and check that it is correctly located, Take great
care not to damage the surface finish of the prima.
ry piston since this could cause leakage past the se-
condary cup,
Fit the plain washer (23) into the cylinder bore
against the circlip, followed by the secondary cup
(24).
Place the nylon guide bearing (25) in position and
secure with the outer cirelip (26), Fit the gasket
(27) and the washer (28).
Mount the return spring (8) and the spring retainer
(30) on the primary piston (9). Compress the spring
until the piston circlip groove is visible behind the
spring retainer and locate the spiral circlip (29).
Ease the spring clip (34) into the non-return vaive
body and check that it is correctly positioned, Fit
the return spring over the valve body and locate
the parts within the outlet port, inserting the spring
first.
Screw the outlet adapter (31), together with the
gasket (35) into the outlet port and tighten to a
torque of 38 Nm (28 ft.-1b., 3.8 kpm). Adopt the
same procedure for the remaining outlet port,
Place the brake fluid reservoir (5) in position to-
gether with the gaskets, and tighten the four bolts.
Febr 1977
Page 457
As from model 1971
DISMANTLING
1. Separate the power assist unit from the master cylinder
by backing off the nuts from the two retaining bolts.
2. Remove the lock ring (20) that holds the primary pis-
ton (12) in place.
3. Back off the stop screw (13).
4, Pull out the primary piston (12) with spring (5) and
the secondary piston (4) with spring (5) and seals.
5. To change the seal ring (6) on the primary piston, the
screw (9) with spring must be completely unscrewed
and the spring retainer, support ring and support wash-
er removed to gain access to the seal ring,
6. Clean the parts in brake fluid or methylated spirit,
INSPECTION
1. Check that the cylinder bore is not scratched.
2. Check that the through flow holes are clear by testing
with a fine iron wire.
3. Check all parts and exchange any that are worn or de-
fective.
Rubber gaskets and seals should be replaced by new ones.
Repair kits containing complete replacement sets of rub-
ber gaskets and seals are available.
REASSEMBLY AND INSTALLATION
(Dip all parts in brake fluid before assembling.)
Insert the primary piston (12) with spring and seals.
Fit the lock ring (10).
Bolt the master cylinder to the power assist unit.
Cover all openings to keep dirt out of the cylinder
during installation.
6. Fit the master cylinder complete with power assist
unit to the dash panel and connect the push rod to
the brake pedal.
7. Connect the brake lines.
8. Connect the vacuum hose and the clip that holds
the speedometer cable to the power assist unit.
9. Mount the air cleaner.
10. Fill the container with brake fluid and bleed the
SE WD
system.
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3 4 5 Z
MASTER CYLINDER, AS FROM MODEL 1971
i 8. Sleeve
1. Container
2. Rubber seal 9. Screw
3, Housing 10. Lock ring
iston 11, Seal ring
. — ‘ 12, Primary piston
6. Piston seals 13. Screw
7. Washer
SAAB
Febr 1977
521-7
Insert the secondary piston (4) with spring and seals.
Page 458
BRAKE LINES
The brake pipes are of 3/16 in. Bundy tube. The ends of
all the pipes are flanged and fitted with compression nuts
which must be passed onto the pipes before the ends are
flanged. It is important to ensure that the pipes are prop-
erly flanged so that there will be no leakage at the joints,
For reasons of safety, it is essential that all pipes, rubber
hoses and connections in the brake system be kept in
first class condition at all times. Bearing this in mind
check regularly that the hoses have not been demand by
flying stones or by abraison. Pipes, too, must be installed
so that they cannot rub or chafe against anything.
Check that the pipes are correctly arranged beneath the
rear seat, and that the pipes do not rub against plating.
All pipe and hose connections must be properly tight-
ened to ensure leak free joints. Make sure that the copper
gaskets in the pipe connections are flawless, and change
any defective ones. Copper gaskets which have become
so hard that they no longer seal effectively may, how-
ever, be annealed and reused.
Pipes which are to be installed must fit well at both ends
and at the clips. Never stretch a badly fitting pipe by
means of the compression nuts or bend an already fitted
pipe. Both of these courses could give rise to stresses
which may result in leakage, pipe fracture or stripped
threads.
Pipes for connection to brake hoses are flanged as per
type “A”. Other pipes are flanged as per type oid = 1
A 8
FLANGING OF BUNDY TUBE
Febr 1977
orates two front and two rear
The brake system incorp
tween the
brake hoses, affording the communication be
body and the wheel cylinders, These hoses are of diffe-
rent lengths and must not be confused. Install the hoses
with the wheels freely suspended and aligned straight
ahead. When tightening the brake pipe, hold the brake
hose nipple (not the locking nut) to prevent the hose
from twisting and changing position.
WARNING
When fitting brake hoses it is highly important to
position them correctly, thereby ensuring that steer-
ing or suspension movements do not bring them in-
to contact with other parts of the car. The brake
hoses must not be wrung or twisted but shall be
mounted in a neutral position. In addition, see to it
that the front hoses form a downward directed curve.
———————
522-1
=-=S
===
— =
=
Page 459
WHEEL CYLINDERS
GENERAL
All work on the brake system must be done under condi-
tions of scrupulous cleanliness and carefulness, See sec-
tion 520.
REAR WHEEL CYLINDERS
The Saab 96 is equipped with smaller wheel cylinders at
rear than those of the Saab 95.
The location of their steady pins differs from that of the
Saab 95 — with a view to avoid misfitting.
As from model 1970, Saab 95 is equipped with rear wheel
brake cylinders of the same dimension (5/8") as those
earlier used in the Saab 96.
WARNING
The steady pin must not be removed, same securing
the wheel cylinder to the backplate.
REAR WHEEL CYLINDER
1, Piston cup 4. Retainer
2. Piston 5. Brake hose connection
3. Rubber boot 6. Bleeding nipple
Febr 1977
Removal
1, Remove the wheel, brake drum and brake shoes.
2. Disconnect the hand brake wire from the levers.
3. Disconnect the brake line from the rear of the back
plate,
4. Remove the wheel cylinder retaining ring and the
bleed nipple from the rear of the back plate.
5. Remove the wheel cylinder.
Disassembly
1. Remove the rubber boots from the cylinder.
2. Pull out the pistons.
3. Take the rubber seals off the pistons.
Inspection
1. Clean the parts in brake fluid or methylated spirit.
Wipe the parts dry.
NOTE
Do not allow gasoline or oil come into contact with
the rubber sealing rings or boots.
. Check that the cylinder bore is unscored.
3. Check that the rubber sealing rings and boots are flaw-
less. The use of unsuitable brake fluids can cause rub-
ber parts to swell. Any rubber parts that are even
slightly damaged or swollen must be renewed.
N
523-1
Page 460
Reassembly
Scrupulous cleanliness must be observed when reassem-
bling the wheel cylinder. Lubricate the cylinder bore,
seals, cups and pistons with brake fluid before reassem-
bling. Reassemble as shown in the illustration, making
sure that the piston seal is facing the right way. Use the
fingers only.
1 2 3 $719 5 714
REAR WHEEL CYLINDER
1, Rubber boot 4. Locking washer
2. Piston 5. Bleed nipple
3. Piston seal
FITTING THE HANDBRAKE LEVER
Remember to bleed the system whenever a brake line or
a wheel cylinder has been removed.
Installation
1. Refit the wheel cylinder to the back plate and locate
the retaining ring and bleed nipple. The cylinder has
a steady pin, a hole to receive this being provided in
the back plate.
DISC BRAKES
Removal of brake pistons and seals
For this task, a special screw wise tool 78 60 430, will be
required.
ATTACHMENT OF REAR WHEEL CYLINDER
SCREW VISE
Tool 78 60 430
2. Reconnect the brake line.
3. Refit the brake shoes, brake drum and wheel, taking
great care not to damage the axle seal.
4. Reconnect the handbrake wire. Note that the hand
brake lever must be installed with the bent part facing
upwards.
523-2 SAAR
Febr 1977
7 —