Chapter 1 Routine maintenance and servicing

Braking system 9•34 Withdraw the pads from the caliper pistonhousing or anchor bracket. The outer pad willnormally remain in position in the anchorbracket, but the inner pad will stay attached tothe piston in the caliper, and may need to becarefully prised free. If the old pads are to berefitted, ensure that they are identified so thatthey can be returned to their originalpositions.5 Brush the dust and dirt from the caliper andpiston, but do not inhale it, as it is a healthhazard. Inspect the dust cover around thepiston for damage and for evidence of fluidleaks, which if found will necessitate caliperoverhaul as described in Section 3.6 If new brake pads are to be fitted, thecaliper piston will need to be pushed backinto its housing, to allow for the extra padthickness - use a C-clamp to do this. Notethat, as the piston is pressed back into thebore, it will displace the fluid in the system,causing the fluid level in the brake mastercylinder reservoir to rise and possiblyoverflow. To avoid this possibility, a smallquantity of fluid should be removed from thereservoir. If any brake fluid is spilt onto thebodywork, hoses or adjacent components inthe engine compartment, wipe it clean withoutdelay.An ideal way to remove fluidfrom the master cylinderreservoir is to use a cleansyringe or an old poultrybaster.7 Prior to refitting, check that the pads andthe disc are clean. Where new pads are to beinstalled, peel the protective backing paperfrom them. If the old pads are to be refitted,ensure that they are correctly located asnoted during their removal.8 Locate the inner and outer brake pad intoposition in the caliper. Relocate the caliperinto position on the anchor bracket, and insertthe mounting bolts.9 Tighten the mounting bolts to the specifiedtorque, and refit the blanking plugs. Relocatethe caliper support spring.10 Repeat the procedure on the oppositefront brake.11 Before lowering the vehicle, check thatthe fluid level in the brake master cylinderreservoir is up to the “Maximum level” mark,and top-up with the specified fluid type ifrequired (see “Weekly Checks”). Depress thebrake pedal a few times to position the padsagainst the disc, then recheck the fluid level inthe reservoir and further top-up if necessary.12 Refit the roadwheels, then lower thevehicle to the ground. Tighten the roadwheelretaining nuts to the specified torque.13 To allow the new brake pads to bed-inand reach full efficiency, a running-in period ofapproximately 100 miles or so should beobserved before hard use and heavy braking.3 Front brake caliper - removal,overhaul and refitting4Note: Before starting work, refer to thewarning at the beginning of Section 13concerning the dangers of hydraulic fluid, andto the warning at the beginning of Section 2concerning the dangers of asbestos dust.Removal1 Chock the rear wheels then jack up thefront of the car and support it on axle stands(see “Jacking and Vehicle Support”). Removethe front roadwheels.2 Fit a brake hose clamp to the flexible brakehose leading to the front brake caliper. Thiswill minimise brake fluid loss duringsubsequent operations.3 Loosen by half a turn, the union on thecaliper end of the flexible brake hose.4 Remove the front brake pads as describedin Section 2.5 Support the caliper in one hand, andprevent the brake hose from turning with aspanner in the other hand. Unscrew thecaliper from the hose, making sure that thehose is not twisted unduly or strained (seeillustration). Once the caliper is detached,cover or plug the open hydraulic unions tokeep them clean.6 If required, the caliper anchor bracket canbe unbolted and removed from the spindlecarrier (see illustration).Overhaul7 With the caliper on the bench, wipe away alltraces of dust and dirt, but avoid inhaling thedust, as it is a health hazard.8 Remove the piston from its bore byapplying low air pressure (from a foot pump,for example) into the caliper hydraulic fluidhose port. In the event of a high-pressure airhose being used, keep the pressure as low aspossible, to enable the piston to be extracted,but to avoid the piston being ejected tooquickly and being damaged. Position asuitable piece of wood between the caliperframe and the piston to prevent thispossibility. Any fluid remaining in the caliperwill probably be ejected with the piston.9 Using a suitable hooked tool, carefully extractthe dust cover from its groove in the pistonand the seal from its groove in the caliper bore,but take care not to scratch or damage thepiston and/or the bore in the caliper.10 Clean all the parts in methylated spirit orclean brake fluid, and wipe dry using a cleanlint-free cloth (see illustration). Inspect thepiston and caliper bore for signs of damage,scuffing or corrosion. If these conditions areevident, renew the caliper body assembly.11 If the components are in satisfactorycondition, a repair kit which includes a newseal and dust cover must be obtained.12 Lubricate the piston bore in the caliperand the seal with clean brake fluid. Carefullyfit the seal in the caliper bore, using fingersonly (no tools) to manipulate it into position inits groove. When in position, check that it isnot distorted or twisted.13 Locate the dust cover over the piston sothat its inner diameter is engaged in the pistongroove. Smear the area behind the pistongroove with the special lubricating greasesupplied in the repair kit, then insert the pistoninto the caliper. Push the piston into position inthe bore, and simultaneously press the dustcover into the piston housing so that it is seatedcorrectly. Take particular care not to distort ordamage the seal or cover as they are fitted.Refitting14 If the anchor bracket was removed, fit itinto position on the spindle carrier, and tightenthe retaining bolts to the specified torque.93.5 Hold the brake hose with a spannerand unscrew the caliper from the hose3.6 Undoing a brake caliper anchorbracket bolt3.10 Brake caliper and piston componentsA Dust cover C PistonB Piston seal D Brake caliper1595Ford Fiesta Remake