At DMG Motorsports, we present the All Balls Front Master Cylinder Rebuild Kit 21-81145 — the trusted fix for a leaking or under-performing dual disc front brake master cylinder on select Harley-Davidson models. Rather than replacing an entire master cylinder assembly, this kit lets you restore factory-level braking performance at a fraction of the cost by renewing every wear-prone internal component. All Balls Racing engineers each rebuild kit to meet OEM specifications, so you get a precise fit and reliable seal every time you service your brake system.

This kit corresponds to Harley-Davidson OEM reference 42736-08 and is designed for handlebar-mounted, dual disc front master cylinders found on a wide range of Softail, Dyna, and Sportster XR1200 models, including the Fat Bob, Low Rider S, Low Rider ST, Low Rider El Diablo, FXDR 114, CVO Pro Street Breakout, and XR1200/XR1200X. Whether your brakes feel spongy, are leaking fluid, or simply haven't been serviced in years, this rebuild kit gives you everything needed to bring your master cylinder back to like-new condition.

Features:

• Complete rebuild kit contains all parts needed to re-seal a leaking front master cylinder
• Includes cup seals, copper washers, O-rings, and replacement screws where applicable
• Built to meet OEM specifications for a precise, reliable fit
• Designed for dual disc, handlebar-mounted front master cylinders (OEM ref. 42736-08)
• Fits select Harley-Davidson Softail, Dyna, and Sportster XR1200 models
• 100% new components — no used or reconditioned parts
• An affordable alternative to replacing the entire master cylinder assembly
• Backed by All Balls Racing's reputation for quality powersports brake and hydraulic components

Fitment