GEATaaT Front Brake Master Cylinder Rebuild Kit 11/16" Bore for Harley Dual-Disc — Seals & Pistons Restore OEM Lever Feel

A complete rebuild kit for the 11/16" bore front brake master cylinder used on select Harley-Davidson dual-disc motorcycles from 1996–2017, designed to restore OEM-style sealing and lever feel.

This GEATaaT rebuild kit contains the seals, O-rings, cups and hardware needed to service the front brake master cylinder found on many Harley-Davidson dual-disc models. It’s engineered to match the 11/16" bore configuration and is intended specifically for Harley dual-disc applications — not for single-disc machines or certain dresser, trike, XL and VRod families. The parts are manufactured to durable standards so you can replace worn internal components without replacing the entire master cylinder assembly.

Which Harley models will this rebuild kit fit?

This kit fits Harley dual-disc front brake master cylinders across a range of model years and families, provided the master cylinder uses an 11/16" bore. It does not fit single-disc models or VRod, or specified dresser/trike/XL exceptions listed below.

• Compatible families: Dyna (1999–2017), Electra Glide (1996–2007), Road Glide (1998–2008), Road King (1996–2007), Sportster 883 (2002–2003), Sportster 1200 (1996–2003), Street Glide (2006–2007), Tour Glide (1996).
• Not compatible with: 2008–2017 dressers, 2009–2013 FL Trike, 2004–2017 XL dual disc variants, HD VRod, and single-disc models.
• Verify your master cylinder bore size (11/16") before ordering to ensure correct fitment.

What components are included and how do they restore braking function?

The kit supplies all internal elastomers and related items that typically wear: piston cups, dust boots, reservoir seals and O-rings. Replacing those parts removes leaks, restores internal sealing and helps recover consistent lever travel and pressure feel.

• New piston cups and seals to re-establish hydraulic integrity.
• Dust boots and reservoir seals to prevent contamination and fluid loss.
• O-rings and small hardware to replace any brittle or damaged pieces inside the bore.

How difficult is installation and what tools will I need?

Installation is a moderate DIY job for anyone comfortable with brake system work and bleeding brakes afterward. Expect to disassemble the master cylinder from the handlebar, change the internal parts, then bench-bleed and reinstall the unit; if you’re unsure, a qualified mechanic should perform the job.

• Common tools: metric wrenches, pliers, screwdrivers, and a bench vise or soft-jawed clamp.
• Consumables: DOT brake fluid compatible with your Harley, clean rags, and a catch container for old fluid.
• Safety note: always follow proper brake-bleeding procedures and torque specs for reassembly.

Why buy a rebuild kit instead of replacing the entire master cylinder?

A rebuild kit is a cost-effective way to restore performance when the cylinder bore and external housing are serviceable. It preserves original master cylinder hardware and avoids the greater expense of a new unit, while providing the critical sealing pieces that usually cause leaks and spongy lever feel.

• Lower cost than a full replacement master cylinder.
• Maintains original OEM housing, lever geometry and mounting hardware.
• Faster turnaround than sourcing a specific new master cylinder for older models.

Who this is for: This GEATaaT 45072-96 rebuild kit is aimed at Harley owners, independent mechanics and restoration shops working on dual-disc front brake systems from the listed model years who need to refresh worn seals and restore braking consistency. If your bike uses an 11/16" bore dual-disc master cylinder and shows signs of leaking, reduced lever firmness, or internal wear, this kit offers the internal components to rebuild the unit—just confirm fitment exclusions before purchase.