Chapter 1 Routine maintenance and servicing

1595Ford Fiesta Remake9•8 Braking system9.7 Removing the secondary pistonretaining pin9.8a Removing the primary pistonassembly from the master cylinder . . .9.8b . . . followed by the secondary pistonassembly7 Using a suitable socket, firmly press theprimary piston into the master cylinder untilthe secondary piston retaining pin becomesvisible through the secondary piston reservoiropening. Remove the retaining pin usingneedle-nosed pliers or similar tool (seeillustration).8 Remove the primary and secondary pistonsby shaking or gently tapping the mastercylinder (see illustrations).9 Examine the piston and cylinder boresurfaces for scoring or signs of metal-to-metalrubbing. If evident, renew the master cylinderassembly as a complete unit.10 Cleaning of components should be doneusing clean brake hydraulic fluid ormethylated spirit - nothing else.11 Obtain a master cylinder repair kit, andbrake fluid reservoir seals.12 Having dipped the secondary pistonassembly in clean hydraulic fluid, insert it intothe master cylinder. Note that the seals on thesecondary piston have raised lips which faceaway from each other, towards the extremitiesof the piston (see illustration). A slighttwisting action will assist insertion.13 Using a suitable socket bar extension, orsimilar tool, press the secondary piston intothe master cylinder to enable fitting of thesecondary piston retaining pin.A Brake fluid reservoirB Reservoir sealsC Secondary piston retaining pin14 Dip the primary piston assembly in cleanhydraulic fluid and, using a similar twistingaction to that used for the secondary piston,insert it into the master cylinder. Note thatboth the seals fitted to the primary pistonhave raised lips that face the same way -towards its captive spring.15 Insert new brake fluid reservoir seals tothe master cylinder then, using a similar rollingaction to that used to remove it, fit thereservoir to the master cylinder.16 It is recommended that a small quantity offluid is now poured into the reservoir and thepistons depressed several times to prime theunit.Refitting17 Locate the master cylinder to the servounit, having fitted a new dust cover asapplicable. Refit the two spring washers andnuts, then tighten to the specified torque.18 Remove the blanking plugs fitted onremoval of the unit, then reconnect the brakepipes, tightening the unions securely.Additionally, on vehicles equipped with antilockbrakes, reconnect the modulator returnhoses to the brake fluid reservoir inaccordance with their colour coding (seeparagraph 2), pushing the hoses firmly intothe reservoir body then levering out the collarsto retain.9 .12 Exploded view of master cylinder componentsD Master cylinderE Secondary pistonF Primary piston19 Refill the brake fluid reservoir with freshfluid of the specified type, then bleed thebraking system in accordance with Section 13or 14, as applicable.20 On completion, ensure that the brake fluidlevel is up to the MAX mark on the reservoirbefore refitting the reservoir cap and thewarning indicator wiring multi-plug.10 Brake pedal -removal and refitting1Removal1 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).2 Remove the clip securing the brake servooperating link pushrod to the brake pedal,noting the bush fitted in the pedal, anddisconnect the brake stop light switch wiringconnector. Release the brake stop light switchin a clockwise direction, and extract it fromthe pedal bracket.3 Remove the C-clip from its pedal shaftlocation, at the right-hand side of the brakepedal, to allow the shaft to be withdrawntowards the centre of the vehicle.4 As the pedal shaft is withdrawn, remove thebrake pedal from the servo operating linkpushrod. The brake pedal spacer can now beslid off the shaft if required, and the brake rodbush removed.5 Prise the bushes out from both sides of thebrake pedal, and renew as necessary.Refitting6 Prior to refitting, apply a small amount ofmolybdenum disulphide grease to the pedalshaft.7 Refitting is the reverse sequence toremoval, ensuring that the brake rod bush islocated correctly, and that the pedal shaft “D”section locates into the pedal box right-handsupport.8 When refitting the stop light switch, insertthe switch into its retainer, press it lightlyagainst the brake pedal until all free play isjust taken up, then turn the switch clockwiseto secure. Reconnect the switch wiringconnector.