
These master cylinder repair kits from AP Racing are the ideal solution for reconditioning old or leaking master cylinders. A far cheaper alternative to replacing the whole cylinder the kits come complete with all seals and fittings required.
Compatiable Master Cylinders:
- CP2623
- CP4400
- CP4623
- CP5623
- CP6093
Contents of Repair Kit:
- Primary Seal
- Piston Washer
- Secondary Seal
- Circlip
- Dust Boot
Instructions:
In reference to the attached image,
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Remove rubber boot (11) and circlip (10)
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Carefully remove internal components
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Replace the following (making sure all seals have been lubricated with brake Fluid);
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Primary Seal (4)
-
Piston Washer (5)
-
Secoundary Seal (7) (Care must be taking when assembling seals as damage maybe caused)
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Check bore is free from debris
-
Lubricate bore with Brake Fluid
-
Reassemble internal components into body
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Use new circlip (10) to secure internal components and new boots to protect from debris (11).

| Brand | AP Racing | |
|---|---|---|
| Option | SKU | Barcode |
| 14.00mm | CP2623-88RK | |
| 15.00mm | CP2623-89RK | |
| 16.80mm | CP2623-905RK | |
| 15.90mm | (.625") | 5/8" | CP2623-90RK | |
| 17.80mm | (0.70") | CP2623-91RK | |
| 19.10mm | (0.75") | 3/4" | CP2623-92RK | |
| 20.60mm | (.812") | 13/16" | CP2623-930RK | |
| 22.20mm | (.875") | 7/8" | CP2623-94RK | |
| 23.80mm | (.937") | 15/16" | CP2623-95RK | |
| 25.40mm | (1.00") | CP2623-96RK | |