Girling Remote Reservoir Master Cylinder, 0.625″, 0.700″, 0.750″ Bore, Non-Integral

Girling remote reservoir master cylinder

Genuine Girling aluminum master cylinders designed to run a remotely mounted fluid reservoir, available in three bore sizes. Select your bore above. The non-integral casting is the one to choose when there is no room for a reservoir on top of the cylinder, when you want the fluid mounted higher for bleeding, or when a single reservoir is feeding more than one cylinder.

These are the master cylinders that were standard fitment on competition cars for fifty years, from the 1950’s through the 1980’s. They are perfect for formula and sports racer construction because of their compact size, light weight, and reliability.

Bore sizes and cross references

We list these under the genuine Girling part number stamped on the cylinder body. The bore size is also cast into the side of the casting, so you can identify what you already have without pulling it apart.

Reading the casting: 0.625 in may appear as either 5/8 or 625, 0.700 in as either 7/10 or .70, and 0.750 in as either 3/4 or .75.

Specifications

Typical uses and applications

• Tilton 600 series pedal boxes, and most other pedal box designs on the 2.25 in flange pattern
• Formula and sports racer brake and clutch circuits
• Hydraulic handbrakes and hand-operated clutch assemblies
• Historic and vintage competition cars, where these were often original fitment
• Kit cars and specials — Caterham, Lotus Seven derivatives and similar
• Installations where the reservoir must sit high or remote for bleeding and fluid level visibility

Remote or integral

• Remote reservoir, this cylinder, has a 7/16-20 inlet port and no reservoir on the body. Choose it for tight pedal boxes, for mounting fluid high, or where one reservoir feeds several cylinders. Budget for a reservoir and inlet fitting on top of the cylinder price
• Integral reservoir carries a 1.75 in reservoir molded into the casting and needs no separate plumbing. Simpler and cheaper to install where there is room in front of the cylinder

Both share the same 2.25 in mounting centers, 3/8-24 outlet, 1.375 in stroke and 5/16 in UNF pushrod, so swapping between them is usually a matter of plumbing rather than pedal box modification.

Good to know

• You will need a reservoir. Nothing is included on the inlet side. See the reservoir options below, and note the inlet is 7/16-20 UNF, the same thread as 4AN
• Genuine, and it matters. Girling-pattern clones circulate widely and some cannot be rebuilt at all. Genuine cylinders carry GIRLING cast into the side of the body
• Choosing a bore. A smaller bore gives higher line pressure for a given pedal effort but needs more pedal travel. Larger bores move more fluid per stroke. If you are changing bore size to chase a pedal feel problem, talk to us first — it is often a balance bar or pad compound issue rather than cylinder sizing
• Mount the reservoir above the cylinder. Gravity feed is what keeps the cylinder full and makes bleeding straightforward
• Service them on a schedule. Reseal rather than wait for a failure. Front-running teams rebuild master cylinders at least once a season

You will also need

• A remote reservoir with a 7/16-20 UNF outlet — the AP Racing kits fit Girling cylinders directly in 3.5 in tall, 2.2 oz, 5 in tall, 3.72 oz and 7 in tall, 5.75 oz capacities
• Girling master cylinder repair kits — the matching rebuild kit for every bore size, so you service this cylinder rather than replace it
• Racing brake fluid — fit a new cylinder and bleed the system with fresh fluid
• The rest of the master cylinder range, everything else in Brakes, and the full Girling range at Formula Race Parts