Overhaul
Master Cylinder - OverhaulService Repair No -
Exploded View Of Master Cylinder:
Disassemble
1. Disconnect battery and remove master cylinder from servo.
2. Before commencing overhaul procedure, thoroughly clean master cylinder and inspect outer surfaces for damage and condition, replace complete assembly if necessary.
3. Carefully ease reservoir from master cylinder by rolling it from seals as illustrated. The reservoir is a push fit in master cylinder and secured by seals.
4. Using soft jaws, one either side of master cylinder flange as shown in illustration, clamp flange in a suitable vise
5. Remove water ingress 0-ring seal from master cylinder to servo flange and discard.
6. Hold outside of transfer housing with a suitable pair of pliers, carefully pull, while working pliers in a backwards and forwards rocking motion to ease housing off master cylinder, discard housing and vacuum seal.
7. Remove 2 reservoir seals from master cylinder inlet ports, seals are different and should be noted for assembly. Discard both seals.
8. Remove retaining ring and 0-ring seal from machined outer surface of master cylinder, discard both seal and retaining ring.
9. Remove guide ring from mouth of master cylinder which supports primary plunger assembly and place to one side, the guide ring is not part of master cylinder service kit and is to be reused.
10. Pull primary plunger assembly out of master cylinder.
NOTE: The primary plunger assembly cannot be broken down any further and is serviced as a complete unit. Discard assembly.
11. The secondary plunger assembly will remain at bottom of master cylinder bore, plunger can be easily expelled by tapping assembly on a piece of timber until plunger appears at cylinder mouth, carefully pull plunger out of master cylinder.
12. If swirl tube was not expelled at same time as secondary plunger, repeat above operation to expel it from bottom of master cylinder bore and discard.
13. Clean all parts with a suitable cleaning fluid or unused brake fluid and place cleaned parts onto a clean sheet of paper.
^ Inspect cylinder bore and plungers for signs of corrosion, ridges and score marks.
^ Provided working surfaces are in perfect condition, new seals from a service repair kit may be used.
SECONDARY PLUNGER SERVICE
Disassemble
Remove following components from secondary plunger and discard:
1. Springs.
2. Seal retainer.
3. Recuperating seal (primary cup).
4. Washer
5. L seal.
CAUTION: A small screwdriver with end rounded and polished is required to remove L seal. DO NOT damage secondary plunger.
Assemble
1. Coat new seals in unused brake fluid, then install L seal to plunger.
2. Install washer followed by recuperating seal.
3. Install seal retainer and springs, ensure springs are correctly seated.
ASSEMBLE
CAUTION: It is important that the following instructions are carried out precisely, otherwise damage could be caused to new seals when inserting plungers into cylinder bore. Generous amounts of new brake fluid should be used to lubricate parts during assembly.
NOTE: Thoroughly check that no debris is lodged in fluid passageways and drillings. If debris is found, carefully remove, re-clean cylinder and re-check.
1. Install new swirl tube to bottom of cylinder bore.
2. Lubricate secondary plunger assembly and cylinder bore.
3. Align plunger assembly to cylinder until recuperation seal is located centrally in mouth of bore.
4. Gently introduce plunger with a circular rocking motion, as illustrated. Ensuring that seal does not become trapped, ease seal into bore and slowly push plunger down bore in one continuous movement.
5. Install primary plunger assembly using same method as for secondary plunger, push plunger down bore.
6. Install original guide ring to support primary plunger.
7. Coat a new 0-ring with brake fluid and install into its respective groove on outer location surface of master cylinder.
CAUTION: 0-ring should not be rolled down outer location surface of master cylinder but should be slightly stretched and eased down cylinder and into its groove. Do not over stretch seal.
8. Install a new retaining ring on outer surface of master cylinder, ensuring that serrations of ring are facing mounting flange.
9. Install two new reservoir seals into their respective ports.
10. Install a new vacuum seal to either primary plunger or to bottom of transfer housing bore, open face of seal towards primary plunger guide ring.
11. Lubricate vacuum seal with brake fluid, install transfer housing to master cylinder, push housing fully up to cylinder mounting flange. Do not adjust transfer housing after fitting.
12. Lubricate a new water ingress seal with brake fluid, slightly stretch seal and ease it down housing until seal is in correct position between housing and flange.
13. Roll reservoir into top of master cylinder, reversing procedure described in "Disassemble" step 3 above.
14. Install master cylinder to servo.
15. Bleed brakes.
16. Reconnect battery, and road test vehicle.