Note: Before starting work, refer to the warning at the beginning of Section 2 concerning the dangers of hydraulic fluid, and to the warning at the beginning of Section 4 concerning the dangers of asbestos dust.

Removal
1 Remove the brake pads as described in Section 4.

2 To minimise fluid loss, unscrew the master cylinder reservoir filler cap and place a piece of polythene over the filler neck. Secure the polythene with an elastic band ensuring that an airtight seal is obtained. Alternatively, use a brake hose clamp, a G-clamp, or a similar tool with protected jaws, to clamp the front flexible hydraulic hose.

3 Clean the area around the hydraulic hoseto- caliper union, then slacken the hose union half a turn. Be prepared for fluid spillage.

4 Unscrew the two mounting bolts or upper guide bolt, as applicable, withdraw the caliper from the disc then unscrew the caliper from the flexible hose (see illustration). Plug the hose to prevent loss of fluid.

7.4 Brake caliper mounting bolts - arrowed (DBA Bendix type)

5 Clean the exterior of the caliper.

6 On the Bendix type, unbolt the caliper frame from the cylinder.

Overhaul
7 Prise the dust cover and ring from the end of the piston (see illustrations).

7.7a DBA Bendix type brake caliper components

1 Mounting bolt
2 Caliper assembly
3 Sliding key kit
4 Bleed screw
5 Retaining plate
6 Sliding guide kit with grease 7 Repair kit with grease

7.7b Girling type brake caliper components

1 Mounting bolt
2 Caliper assembly
3 Pad retaining pin and spring 4 Bleed screw
5 Repair kit

8 Withdraw the piston from the cylinder. If necessary use air pressure from a foot pump in the fluid inlet to force the piston out.

9 Prise the seal from inside the cylinder, taking care not to damage the cylinder wall.

10 If required, dismantle the sliding guides.

On the Bendix type unbolt the endplate from the guides and remove the rubber dust covers. Keep the guides identified for location.

11 Clean all the components using methylated spirit or clean brake fluid then examine them for wear and damage. Check the piston and cylinder surfaces for scoring, excessive wear and corrosion, and if evident renew the complete caliper assembly.

Similarly check the sliding guides. If the components are in good condition obtain a repair kit which will contain all the necessary rubber seals and other renewable items.

12 Dip the new seal in fresh brake fluid then locate it in the cylinder groove using the fingers only to manipulate it.

13 Dip the piston in brake fluid and insert it in the cylinder, twisting it as necessary to locate it in the seal.

14 Fit the dust cover and ring over the end of the piston and cylinder.

15 Lubricate the sliding guides with the grease supplied and refit them, together with the new seals. On the Bendix type refit the endplate and tighten the bolts.

16 On the Bendix type, refit the caliper frame and tighten the bolts.

Refitting
17 To refit the caliper, first screw it onto the flexible hose and locate it over the brake disc so that the hose is not twisted.

18 Clean the mounting bolt threads and apply locking fluid. Insert the mounting bolts or upper guide bolt and tighten to the specified torque.

19 Tighten the flexible hose union on the caliper. Check that the hose is clear of the strut and surrounding components and, if necessary, loosen the rigid pipe union on the body bracket, reposition the hose and retighten the union.

20 Refit the brake pads, as described in Section 4.

21 Remove the brake hose clamp or polythene sheeting and bleed the hydraulic system, as described in Section 2.