Page 441
ADJUSTMENT
General
Brake shoe wear is revealed by excessive travel of the
brake pedal or hand brake lever before the brakes work
The distance between the pedal and the lower part of the
dash panel must not be less than the values mentioned in
the pictures, with a pedal pressure of approx. 250 N (55
lb., 25 kp) and the engine idling.
The front wheels have self-adjusting brakes, Consequently
it will only be necessary to adjust the brake shoes on the
rear wheel brakes.
THE MINIMUM DISTANCE PERMISSIBLE BETWEEN DE-
PRESSED PEDAL AND TOE-BOARD
A = 2.6 in. (65 mm)
B = approx. 250 N (55 Ib., 25 kp)
Adjustment of rear brake shoes
1. Jack up the car so that the rear wheels are clear of the
ground. Be sure to locate the jack in the correct posi-
tion. It is possible to adjust the brake without remov-
ing the wheels.
2. Release the handbrake and check that the brake levers
return all the way. If the cable runs sluggishly in its
sheathing, the lever must be pulled off by hand.
Febr 1977
3. Depress the brake pedal hard several times in order to
center the brake shoes.
4. The adjusting screw for the rear brakes consists of a
square peg located on the rear of the backplate. Turn
with a special spanner until the wheel is locked. Then
back off one or more steps until the rear wheel again
rotates freely.
FOOT BRAKE ADJUSTING SCREW, REAR WHEELS
1. Adjustment device
2. Adjustment point
5. After adjusting, check that the free movement of the
pedal is 0.12—0.24 in. (3—6 mm). See section 524.
If the clearance is less than this measure, the brake
shoes don’t return when the brake pedal is released.
6. If the adjusting screw cannot be tightened up enough
to lock the wheel, the brake linings are worn and must
be renewed, Always change brake linings simultaneous-
ly on both wheels and NEVER on one wheel only. The
reason for this is to ensure that the braking effect will
be even. When changing brake linings, always use genu-
ine Saab replacements or linings recommended by Saab.
After adjusting the brakes, always make sure that the rear
wheels revolve easily — this is done by depressing the brake
pedal, releasing it and then rotating the wheels.
511-3
Page 443
BRAKE LININGS
REPLACEMENT
At intervals not exceeding 6 000 miles (10 009 km) the
wheels shall be removed and the thickness of the brake
linings checked. For the brake drums this is made through
the inspection holes. The brake linings should be ex-
changed at a thickness of 0.1 in, (2.5 mm), the friction
pads at 0.06 in. (1.5 mm) thickness of the very lining.
An exchange system is operative for complete brake shoes
Replacement of linings thus calls for exchange of the en-
tire shoe.
If linings only are to be changed, they must be ground in
a special machine to a radius of 0.010—0.012 in, (0,.25—
0.30 mm) less than that of the brake drum in order to en-
sure perfect contact. The ends of the linings must not be
chamfered; the edge should be as sharp as possible,
1. Remove the old brake linings.
2. Wash the brake shoes in gasoline or kerosene and blow
clean with compressed air.
3. Place the new linings on the shoes and fix them with
two rivets in the center.
4, Fix the other rivets in turn, proceeding from the cen-
ter and out towards the ends. Stretch the lining well
to secure good contact with the shoe. Any clearance
left between the shoe and its lining may jeopardize
the function of the brakes and cause unwanted noise.
5. Grind the lining to a radius of about 0.010—0.012 in.
(0.25—0.30 mm) less than that of the drum.
CENTERLESS GRINDING OF BRAKE LININGS
R = Radius of brake drum
r = Radius of brake lining. Th
(0.25—0.30 mm) less than FR
A = Measurement 0,010-0.012 in, (0.25-0.30 mm)
us, to be 0.010--0.012 in,
Febr 1977
rc Se —
NOTE
To secure perfect contact between the fining and
| the drum, and speedy running-in, the linings shout
be ground after riveting to a radius of O010-0.012
in. (0.25—-0.30 mm) less than that of the drum. This
is particularly important when the brake drum has
been machined. Special equipment is required for
this grinding operation.
—
NOTE
The ends of the linings must not be chamfered, but
should have as sharp an edge as possible.
NOTE
To ensure optimal safety, use only genuine Seab
linings or exchange shoes.
WARNING
Do not allow oil or grease to come in contact with
brake linings or drums.
512-1
PETERLRLEESERRTET
Page 444
BRAKE DRUMS
REMOVAL AND INSTALLATION
1.
Remove the cotter pin and the shaft nut,
»
. Jack up the ear,
3, Remove the wheel
4, Release the handbrake and adjust the rear brake shoes
with the adjusting screw,
» Remove the brake drum, using puller 78 40 028,
WHEEL PULLER 78 40 028
6. After refitting the brake drum, tighten the shaft nut
with a torque wrench set at 90 Nm (66 ft.-Ib., 9 kpm).
515—1
MACHINING
If the brake drums are moderately mroreree ex a
less equally on both left and right sides, : ht a
fluence the braking effect or the life of the thik eles
the other hand, only one drum Is scored or ine
severely scored, they should be renewed or a pi
chined, Renewal or machining is also sai he
brake drum is out-of-round, which is betraye ee im KY
pedal action when the brakes are applied. fa pa 2
may be machined to a maximum diameter of 5. i
(204.7 mm).
When new brake drums are being installed, new wheel
bearings should also be fitted.
March 1979
Page 445
BRAKE DISCS
REPLACEMENT
When the brake disc shows signs of heavy wear after con-
siderable mileage, it must be replaced. Moderate scoring,
on the other hand, does not necessitate replacement.
To change the brake disc, proceed as follows:
1. Remove the hub cap and slacken the shaft nut.
2. Jack up the front of the car, take off the wheel and
remove the shaft nut.
3. Remove the two bolts holding the brake housing to
the steering Knuckle housing. These bolts are accessi-
ble from the inside of the brake disc, Lift the brake
housing clear of the brake disc.
DISC BRAKE COMPONENTS
1. Brake body assembly
2. Spring loaded steady pin
3. Support bracket
4, Hinge pin
5, Split pins
6. Spring clip
7. Bleed screw
NOTE
Do not disconnect the brake hose, instead place the
brake housing in such a way that the hose is not ex
posed to tension.
4. Pull off the wheel hub with the brake disc attached,
using wheel puller 7840028.
5. Detach the brake disc from the wheel hub.
Reassemble in reverse order. When refitting the brake
housing bolts in the steering knuckle housing, always use
a new locking plate.
NOTE
After the reassembly, remember to pump repeated-
ly with the brake pedal so that the brake pistons
will move out towards the disc.
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8. Wiper seal
9. Piston
10. Friction pad assemblies
11. Cylinder body
12. Fluid seal
13. Retainer
14. Shim
Febr
1977 SAAB ae
Page 446
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FRONT AXLE UNIT WITH DISC BRAKE
OMNAMNAWNS
. Brake disc
. Brake pad
. Brake piston
. Brake housing
Nut
. Wheel hub
. Outer drive shaft
. Shaft seal
. Steering knuckle housing 18. Spacer ring (on certain cars only)
10. Ball bearing
11. Shaft seal
12, Ball
13. Backing plate
14, Clamp
15. Inner drive shaft
16. Circlip
17. Bellow
Febr 1977
4
Page 447
FRICTION PADS
GENERAL
As the disc brakes are selfadjusting, it is not possible to
decide by the length of the pedal stroke wether the brake
linings are worn. At intervals not exceeding 6 000 miles
(10 000 km) the wheels shall be removed and the thick-
ness of the brake linings checked. The friction pads must
be removed when the thickness of the lining is less than
0.06 in. (1.5 mm).
REPLACEMENT
1. Jack up the car and remove the wheel.
2, Remove the cotter pins, and the spring holding the
friction pads. Remove the friction pads.
3. Clean thoroughly the uncovered part of the piston,
and make sure that there is no rust or dirt on the
friction pads surfaces which contact the bracket
and the yoke,
NOTE
When cleaning, use only brake fluid or methylated
spirit.
4. Drive the piston back into the brake housing with
the aid of screw vise 78 60 430.
PRESSING IN THE BRAKE PISTON
Too! 78 60 430
NOTE
When the brake piston is forced back into the cyl-
inder, the brake fluid level in the reservoir will rise
appreciably, and it may then be necessary to drain
off superfluous fluid.
5. Clean the brake disc thoroughly with trichlore-
thylene.
Febr 1977
t towards the wheel, and
ake sure that it moves
ke. Possibly, protrud-
ed with a file.
6. Turn the movable brake par
fit the outer friction pad. M
freely in its position in the yo
ing parts will have to be trimm
aie
IMPORTANT
If used friction pads are refitted, they must be
placed in their original locations.
7. Turn the movable brake part backwards as far as
possible.
8, Fit damping shims to the bac
and make sure that the shim does not exc
contours of the pressure plate.
9. Be sure that the damping shim is fitted with the two
recesses directed downwards, in such a way that
they are centred on the ends of the piston recess.
Fit the inner friction pad. Also make sure that the
recess in the piston is directed downwards. The
k of the friction pads,
eed the
b brake piston of the latest design has a face ground
contact surface facing the friction pad. In this con-
nection the damping shim has been altered in such
a way that the piston has the corresponding fit-up
facing the friction pad.
10. Fit the spring. The recess in the spring
near as possible to the outer friction pad. Fit new
cotter pins, and lock them.
Fit the upper cotter pin first. When fitting the low-
er cotter pin, press the spring upwards with the aid
of a screwdriver.
shall lie as
INSTALLATION OF BRAKE PADS
NOTE
Fit a new spring, if the old one is worn out.
11. Pump repeatedly with the brake pedal in order for
the friction pads to be adjusted in towards the brake
517-1
sonnes
weet
Page 448
ee
disc,
12. Top up with brake fluid in the reservoir,
WARNING»
Do not forget to pump repeatedly with the brake
pedal, otherwise the pedal will go all the way down
when the brakes are applied,
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Page 449
HYDRAULIC FOOTBRAKE SYSTEM
OVERHAUL
If it is found necessary to dismantle the brake system, or
any part thereof, this must be done under conditions of
scrupulous Cleanliness. Clean off all dirt and grease before
removing any parts. Do not swill a dismantled unit in gas-
oline, kerosene or trichloroethylene, etc., because these
solvents will ruin the rubber parts. Dismantle the units
on a bench covered with a sheet of clean paper. Do not
touch internal parts with dirty hands, particulary rubber
items. After dismantling, place all metal parts in a tray of
clean brake fluid to soak. Having done this, dry off with
a clean, lint-free cloth and lay the parts out in order ona
sheet of clean paper. To ensure unfailing reliability, we
would recommend that all rubber parts be replaced by
new ones. These are ready available in the form of repair
kits containing all the rubber parts required for each par-
ticular unit.
The main bodies of units may be swilled in industrial
methylated spirit or brake fluid, but if spirit is used all
traces must be dried out before reassembly. All internal
parts should be dipped in brake fluid according to Spec.
DOT 3, DOT 4 or SAE J 1703 and assembled wet.
INSPECTION
For reasons of safety, it is of the utmost importance for
the hydraulic system to be checked at regular intervals.
BRAKE FLUID
General
Always keep the brake fluid reservoir properly filled.
Check the level every 6 000 miles (10 000 km) or every
three months, whichever comes first.
It is essential to use the recommended brake fluid. Inferior
brake fluids can seriously damage the entire brake system.
Apart from ruining rubber cups and seals, such fluids may
lack lubricating properties and initiate corrosion. Further-
more, they may be escessively viscous at low temperatures
or have a low boiling point, which would cause vaporiza-
tion in the system upon heavy brake applications. This
would result in brake failure, the consequences of which
would be disastrous.
Febr 1977
Even the best brake fluids deteriorate after prolonged use,
owing to oxidation and absorption of water, which low-
ers the boiling point.
For racing and rallying, and for driving in mountainous
territory, brake fluid should be changed at yearly inter-
vals.
The brake fluid should be changed after any repairs to
the brake system and after 24 000 miles (40 000 km) or
at intervals of two years.
The brake fluid shall always be kept in a closed container.
IMPORTANT
Use only brake fluid satisfying the minimum require-
ments of specifikation DOT 3, DOT 4 or SAE J 1703.
Replenishing
Before unscrewing the filler cap, clean the top part of
the brake fluid reservoir to prevent dirt entering when
the cap is removed. Be careful not to spill any brake fluid
on the paintwork of the car when pouring in brake fluid,
as this fluid is injurious to paint. Check that the air vents
in the filler cap are not chocked.
If brake fluid consumption is found to be excessive, ex-
amine all lines, hoses, connections and cylinders, applying
firm pressure to the brake pedal meanwhile.
Changing
1. Open the primary circuit nipples (left front and right
rear wheel) and connect hoses as when bleeding. ?ump
the brake pedal until the fluid container is almost emp-
ty. Fill new fluid and continue pumping until the en-
tire system is filled with new fluid.
Close the bleed nipples.
Repeat the procedure for the secondary circuit (right
front and left rear wheel). Pump through at least half
a quart (half a liter). Replenish the container.
2. Bleed the brake system.
520-1
Page 450
BLEEDING
Cc ¥Y when pert of the
Orake system has been Gisassembied
enc when the Drake fluid has been drained off Sure signs
that air has entered the system are excessive pedal travel,
springy pedal action or absence of braking effect until the
Orake pedal has been firmly depressed several times,
A bleed nipple is provided for each wheel. Bleed nipples
for the disc brakes are located on the w heel cylinder
LOCATION OF BLEEDING NIPPLE, FRONT WHEEL BRAKE
The best result is obtained with the aid of bleeding equip-
ment. The makers instructions should be followed. Bleed-
ing can also be done according to the following descrip-
tion.
1. Check that the reservoir is completely full of brake
fluid and that the air vents in the reservoir cover are
not choked.
2. Bleed either one wheel at a time or two wheels at the
same time. One circuit should be bled completely be-
fore bleeding of the other circuit is started, Up to and
incl, model 1970 (make Lockheed) the left front wheel
and the right rear wheel must be bled first.
3. Fit suitable hoses to the bleed nipples on both wheels.
4, Dip the hose end in a glass vessel containing clean
brake fluid,
. Back off both nipples 1/2—1 turn,
6. Have an assistant pump the brake pedal and watch un-
LOCATION OF BLEEDING NIPPLES, REAR WHEEL BRAKE til escaping brake fluid is free of air bubbles, Keep the
hose ends below the fluid level in the glass vessel the
whole time,
7. Close the bleed nipples, keeping the pedal depressed
meanwhile.
8. Check that the brake fluid in the reservoir does not
run out while the system is being bled.
9. Top up the reservoir with fresh brake fluid after bleed-
ing the two circuits.
oi
520-2 Febr 1977