Disassembly and Assembly
Master Cylinder - Not ABS:
Lucas Girling - Type 25.4mm AS/AS
CAUTION: This master cylinder is not suitable to be fitted on vehicles with anti-lock brake systems.
REPAIR
1. Thoroughly clean master cylinder and inspect outer surfaces for damage and condition. Renew complete assembly if necessary.
Master Cylinder - Not ABS:
2. Using two soft jaws, clamp master cylinder flange in a suitable vice.
Master Cylinder - Not ABS:
3. Grip outside of transfer housing with a suitable pair of pliers, carefully pull, working pliers in a backwards and forwards rocking motion to ease housing off master cylinder. Discard housing and vacuum seal.
Master Cylinder - Not ABS:
4. Ease reservoir out of master cylinder taking care to ensure that two outlet ports on bottom of reservoir do not become damaged during this process.
5. Withdraw two reservoir seals from master cylinder inlet ports. Note for reassembly these seals are different. Discard seals.
6. Remove retaining ring and O-ring seal from machined outer surface of master cylinder. Discard both seal and retaining ring.
7. Remove guide ring, which supports primary plunger assembly, from mouth of master cylinder. Place to one side for reassembly, note this component is not part of service kit.
Primary Plunger
Master Cylinder - Disassemble:
8. 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.
Master Cylinder - Disassemble:
9. The secondary plunger assembly will remain at bottom of master cylinder bore. Remove tapping assembly on a piece of wood until plunger appears at cylinder mouth, carefully pull plunger out of master cylinder.
10. If swirl tube was not expelled at same time as secondary plunger, repeat above operation to remove it from bottom of master cylinder bore and discard.
11. Clean all parts with unused brake fluid. 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 Girling Service repair kit may be used.
Renewing Secondary Plunger Seals
Master Cylinder - Disassemble:
12. Remove and discard components from secondary plunger.
NOTE: A small screwdriver with end rounded off and polished is required to remove L seal. DO NOT damage secondary plunger.
Secondary Plunger:
13. Coat new seals in unused brake fluid. Fit L seal to plunger.
14. Fit washer followed by recuperating seal. Fit seal retainer and springs, ensure springs are correctly seated.
REASSEMBLY
CAUTION: It is important that 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.
1. Fit new swirl tube to bottom of cylinder bore.
Refitting Secondary Plunger:
2. Lubricate secondary plunger and cylinder bore. Offer plunger assembly to cylinder until recuperation seal is resting centrally in mouth of bore. 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.
3. Fit new primary plunger assembly using same method as for secondary plunger.
4. Fit original guide ring to support primary plunger.
5. Coat a new O-ring with brake fluid and fit to its respective groove on outer location surface of master cylinder.
CAUTION: Do not roll O-ring down outer location surface of master cylinder. It should be slightly stretched and eased down cylinder and into its groove. Do not over stretch seal.
6. Fit new retaining ring on outer surface of master cylinder ensuring that serrations of ring are facing mounting flange.
7. Fit two new reservoir seals in respective ports.
8. Fit a new vacuum seal to either primary plunger or to bottom of transfer housing bore, open face of seal towards primary plunger.
9. Lubricate vacuum seal with brake fluid. Fit transfer housing to master cylinder, push housing fully up to cylinder mounting flange. Do not adjust transfer housing after fitting.
10. Lubricate new water ingress seal with brake fluid, Slightly stretch seal and ease down housing until it is in position between housing and flange.
11. Roll reservoir into top of master cylinder.