Girling master cylinder repair kits
Genuine Girling repair kits for the overhaul of Girling master cylinders, available in all five bore sizes from 0.625 in through 0.875 in. Select your bore size above. One kit reseals one cylinder, and the kits suit integral and non-integral Girling master cylinders in brake or clutch use alike.
A master cylinder weeping past its seals takes pedal feel with it long before it fails outright. If the bore is still good, resealing costs a fraction of a replacement and puts the pedal back where it belongs.
What is in the kit
Each kit contains everything needed to reseal one master cylinder, including the rubber grease for reassembly:
- Piston seal
- Valve seal
- Valve shim
- Snap ring
- Dust boot
- Cap gasket for integral reservoir caps
- Packet of rubber grease
Seals are EPDM, formulated for use with any DOT-rated brake fluid. They are not suitable for use with hydraulic oil.
Bore sizes and part numbers
The repair kit is specific to the bore, and the bore size is cast into the side of the cylinder body. Check the casting before ordering rather than measuring a worn bore. We list these under the genuine Girling part numbers, so what you order is what Girling stamps on the box.
| Bore | Fractional | Metric ID | Girling part number |
|---|
| 0.625 in | 5/8 in | 15.875 mm | PB000625 |
| 0.700 in | — | 17.78 mm | PB000700 |
| 0.750 in | 3/4 in | 19.05 mm | PB000750 |
| 0.812 in | 13/16 in | 20.64 mm | PB000812 |
| 0.875 in | 7/8 in | 22.23 mm | PB000875 |
Not sure which you have? Send us a photo of the casting and we will identify it for you.
Fitment
- Girling integral reservoir master cylinders
- Girling non-integral or remote reservoir master cylinders
- Brake and clutch master cylinder applications alike
- Genuine Girling cylinders only — see the note below
Specifications
| Specification | Detail |
|---|
| Manufacturer | Girling |
| Bore sizes available | 0.625, 0.700, 0.750, 0.812 and 0.875 in15.875 to 22.23 mm |
| Girling part numbers | PB000625, PB000700, PB000750, PB000812, PB000875one per bore size, used as our SKU |
| Fits | Girling integral and non-integral master cylinders |
| Application | Brake or clutch master cylindersracing, historic and road use |
| Seal material | EPDMall DOT-rated brake fluids; not for hydraulic oil |
| Grease included | Yes, packet of rubber grease for reassembly |
| Sold as | One kitreseals a single master cylinder |
Good to know
- Check the bore first. A repair kit only works if the bore is in good serviceable condition. Light staining cleans up with a rotary clean and a flush, but a badly scored bore means the cylinder needs replacing rather than resealing
- Genuine Girling only. These kits fit genuine Girling cylinders, which have GIRLING cast into the side near the bore size. They do not fit the lower-quality clones sold elsewhere
- Reading the casting. The bore size is cast into the side of the body. 5/8 in may appear as either 5/8 or 625, and 3/4 in as either 3/4 or .75
- Rebuild before it fails. Master cylinders should be resealed on a schedule, not after a problem. Front-running teams rebuild theirs at least once a season
- Bleed with fresh fluid. Refill with new racing brake fluid after a rebuild rather than reusing what came out
While you have it on the bench
