Camotokiit Rear Brake Master Cylinder Rebuild Kit for Harley 11/16" Bore — Billet Aluminum Plunger, Pre-Assembled Seal Kit

Complete rear brake master cylinder rebuild kit for 11/16" bore Harley master cylinders, supplied as a pre-assembled billet-aluminum plunger and precision internal parts to restore pedal feel and hydraulic function.

This Camotokiit rebuild kit renews the internal components of compatible rear master cylinders used across many Harley-Davidson Softail, Dyna, FXR, Electra Glide, Road King and Sportster models from late 1987 through 2017. Instead of replacing the whole master cylinder, this kit gives you the internal piston, plunger housing, seals, spring, spacer and snap ring engineered to restore reliable fluid sealing and consistent lever response. The kit replaces several original part numbers so it’s a practical upgrade for routine maintenance or troubleshooting a spongy or leaking rear brake unit.

What exactly comes assembled in this rebuild kit?

The kit arrives as a single assembled unit made from a billet aluminum plunger housing with integrated O-rings, a metal piston, return spring, spacer and retaining snap ring. The listing shows the discrete pieces before assembly, but the shipped item is ready to install into the master cylinder bore.

• Billet aluminum plunger/piston housing with factory-fit O-rings
• High-strength metal piston matched to the 11/16" bore
• Sealing rings, internal spring, spacer and snap ring pre-installed
• Replaces HD part numbers in the 42382-87 series

Which models and years will this Camotokiit kit fit?

Designed for the 11/16" bore rear master cylinders found on a long list of Harley-Davidson models, the kit covers late 1987 through 2017 production ranges depending on the model family. Check the extensive fitment list for precise model-year matches before ordering.

• Softail, FXST/FLST and many Softail variants (late 1987–2017)
• Dyna and FXD families (1991–2017) and many FXR models (late 1987–2000)
• Electra Glide, Street Glide, Road Glide, Road King and Tour Glide models (1992–2007+ where specified)
• Sportster 883/1200 series (late 1987–2003) and related early Sportster variants

How does replacing the internal assembly help braking performance?

Wear, corrosion or hardened seals inside the master cylinder can allow fluid bypass or prevent full piston return, causing a soft lever or intermittent braking. Installing a new pre-assembled internal unit restores original seals and mechanical tolerances, improving pedal firmness and hydraulic responsiveness without replacing the complete reservoir or external body.

• Eliminates leakage paths caused by worn seals and O-rings
• Restores consistent piston travel and return spring tension
• Improves pedal feel and reduces sponginess under load
• Cost-effective alternative to a full master cylinder replacement

What should I know before installation?

Basic mechanical skill and a clean workspace are recommended. This kit is for rear master cylinders with an 11/16" bore—verify bore size and model-year fitment first. Always follow safety procedures: bleed the brake system after installation and use compatible DOT brake fluid.

• Confirm 11/16" bore and model-year compatibility before purchase
• Requires brake bleeding and fluid replacement after install
• Inspect surrounding components (lines, caliper, ABS sensors) while servicing
• Use correct DOT fluid and torque specifications per service manual

Who this rebuild kit is for: Riders, mechanics and restoration shops wanting a reliable, OEM-replacement-style internal assembly for rear master cylinders on a wide range of Harley touring, cruiser and sport models. It’s ideal for owners repairing leaks, restoring firm pedal feel, or performing preventive brake maintenance without buying a full new master cylinder body.