7/8 Master Cylinder Rebuild Kit

Don't replace it — rebuild it. This 7/8" master cylinder rebuild kit is everything you need to restore proper brake feel and function to the MCP master cylinders found on most quarter midget race cars. 

The kit is designed to fit the MCP 875 and MCP 18875 (billet) master cylinders — the two most common units running in quarter midget competition. Whether you're dealing with a spongy pedal, fluid leaks, or a cylinder that's just due for a seasonal refresh, this kit brings it back to like-new performance with fresh internal components.

Inside the kit you'll find the seals, o-rings, piston, return spring, fill cap, and dust boot needed for a complete rebuild. Following MCP's standard rebuild procedure — cleaning the bore, lubricating with fresh brake fluid, and carefully seating the new piston and seal — takes most experienced crew members under an hour on the workbench.

Rebuilding your master cylinder at the start of each season (or any time you notice inconsistent pedal feel) is a low-cost way to maintain reliable, predictable braking — which matters whether your driver is in Rookie or running for a national title.

Compatible With:

• MCP 875 cast master cylinder
• MCP 18875B billet master cylinder (7/8" bore)
• Most quarter midget brake systems using MCP components

Kit Includes:

• Piston (7/8" bore)
• Return spring
• Cup seal(s) and o-rings
• Dust boot
• Fill cap

Brake Fluid Note: Fluid compatibility depends on which seals are included in the specific kit variant. Our kits require you to use DOT 5 silicone brake fluid only.