Billet CNC Brake Master Cylinder Cap – Harley Big Twin & Sportster

Upgrade your Harley with a precision CNC-machined billet brake master cylinder cap. Made from aircraft-grade 6061 aluminum, this cap provides lightweight strength and a sleek, custom look. The cap features breather cutouts underneath for optimal performance and a deep-engraved MM logo on top for a bold, finished appearance.

Designed to replace stock caps, it fits a wide range of Harley models:

Front Brake:

• Big Twin & Sportster, Late 1985–1995
• Replaces HD# 45004-85

Rear Brake:

• FLST & FLSTF, Late 1987–1999
• Dyna, 1991–2005
• Replaces HD# 45004-85

Rear Brake (Sportster):

• Late 1987–2003
• Replaces HD# 42381-87

• CNC machined from 6061 aircraft-grade aluminum
• Lightweight and strong for long-lasting performance
• Breather cutouts underneath
• Deep-engraved MM logo on top
• Direct replacement for stock caps
• Fits multiple Big Twin, Sportster, and Dyna models
• No hardware included

• Aftermarket billet replacement, not OEM
• Hardware not included; use existing brake cap bolts
• Verify fitment with your model before installation