Opel 1900 1973, Service Manual

Page: 274 / 625

DISC BRAKES 15
Condition Possible Cause
2. Binding brake pedal
mechanism.
Correction
2.
Check and lubricate, if
necessary.
3. Corroded caliper
assembly.
3. Clean and lubricate.
MAINTENANCE AND ADJUSTMENTS
DISC BRAKE MAINTENANCE
Checking Brake Fluid Level
The brake fluid level in the brake fluid container
must be checked during inspection, then
every 3,000 miles during inspection and preventive
maintenance servicing.
The brake fluid level must not be higher than the
inscription “MAX” and must be at least up to
“MIN”. Replenish brake fluid, if necessary.
Because of the relatively large brake caliper bore
cross section and the self-adjustment of the disc
brakes, resulting in a greater piston travel to compen-
sate for friction pad wear, the brake fluid level drops
faster than in fluid containers for drum brakes with
their smaller wheel brake cylinders. For this reason
pay special attention to the fluid level in the
brake
fluid container.
Drop of brake fluid level can be due to friction pad
wear and may not be due to leakage in the braking
system.
On loss of brake fluid due to leakage, the brake sys-
tem must be checked thoroughly.
Friction Pad Adjustment
Friction pad adjustment is not necessary on the front
wheel disc brakes as this is done automatically by the
pistons in the brake calipers.
Lubricating Front Wheel Bearings
When removing one or both brake discs, check lu-
brication of front wheel bearings and the cavity of
the wheel hub and replenish if necessary (see operat-
ion
“Removing and Reinstalling Brake Disc”).
When carrying out other work on disc brakes which
does not necessitate the removal and installation of
the brake disc, lubricating wheel bearings is not
necessary.
Checking Disc Brake Friction Pads for Wear
Whenever a disc brake equipped car is in for periodic
service, while the car is raised, the friction pads in
both brake calipers should be checked for wear by
making a simple measurement. Worn or oily friction
pads must be replaced.
Measure friction pad wear as follows:
1. Remove friction pads.
2. Using a one-inch micrometer, measure the thick-
ness of the pad and friction plate. See Figure
Figure Checking Brake Friction Pad Thickness
3. If any one of the four measurements is less than
replace all four friction pads. (Partial replace-
ment of friction pads would cause unequal braking.)
Removal and Installation of Friction Pads
1. Raise car and remove front wheels.
2. Drive dowel pins out of brake calipers toward
center of car. See Figure Dowel pins must be
driven inward because they are secured by enlarge
fluted inner ends.
3. Remove friction pads from brake calipers. See
Figure