Brake Pad: Service and Repair

Fig. 1 Teves disc brake caliper, exploded view:

Fig. 2 Girling disc brake caliper, exploded view:

These models use two types of opposed piston fixed brake calipers, one is Girling, the other Teves. Refer to Figs. 1 and 2, for service procedures on these calipers. The friction pads must be checked for wear every 7500 miles. Pads that have worn down to the thickness of 0.79 in (2 mm), must be replaced with new ones.

NOTE: All four friction pads must always be renewed together. It is not permissible to renew single friction pads or both pads of only one wheel. In addition, the spreader springs of both calipers must also be renewed with the friction pads. All necessary parts are usually furnished in a repair kit.

REMOVAL

1. Remove front wheel.
2. Using a punch, drive out pad upper retaining pin.
3. Remove pad spreader spring.
4. Using a punch, drive out pad lower retaining pin.
5. Pull pads out of caliper, using a suitable hook. If the friction pads are to be reused, they must be marked as it is not permissible to change the pads from the outside to the inside and vice versa or from the right to the left wheel.

INSTALLATION

1. Oily friction pads and those with deep cracks or which have become detached from the metal plate must be renewed. In this case, all four friction pads must be renewed.
2. If pads are to be reused, remove excess dirt from grooves.
3. Push both pistons into their end positions with retaining pliers. When doing this, the brake fluid behind the piston in the cylinder is forced back into the fluid reservoir. To prevent the reservoir overflowing, some of the fluid must be removed from the reservoir with a container that is used only for brake fluid. Brake fluid is poisonous and must not be siphoned off with a hose.
4. Clean seating and sliding surfaces of friction pads in brake caliper. To do this, remove piston retaining plates. Never use petroleum products for cleaning. After cleaning, blow out with compressed air.
5. Check rubber boot for damage. Hardened, brittle or cracked boots must be replaced. To replace a rubber boot the brake caliper must be removed.
6. Check brake disc for wear.
7. Insert pads into brake caliper. The pads must be free enough to move to freely in caliper.
8. Insert pad lower retaining pin into caliper. The retaining pin must not be driven in with a punch smaller in diameter than the pin as the front shoulder can easily be sheared off by the split clamping bushing. It is advisable to drive in the retaining pins with a hammer only and no additional tools.
9. Install new pad spreader spring.
10. Push in pad upper retaining pin after first pressing spreader spring down with thumb. Depress brake pedal several times while vehicle is stationary to enable pistons and pads to assume their correct positions to the brake disc.