Saab 95 1967, Service Manual

Page: 449 / 610

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 on a
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.
Flhr 1077
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. Pump
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