Hayes Dominion A4 4-Piston Disc Brakes

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  • Regular price $759.95 CAD

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The Hayes Dominion A4 master cylinder is engineered to achieve the shortest possible dead stroke and a sharp, responsive bite point right out of the factory. The Dominion A4 caliper features a four-piston design, optimized for maximum structural rigidity. This is achieved through a cold-forged caliper and the inclusion of a KingPin structural pad retention bolt, which significantly enhances stiffness.

Inspired by motorsports, the Two-Stroke dual port bleed system, combined with top-tier DOT 5.1 fluid and a Kevlar-reinforced hose, ensures the hydraulic system delivers peak performance under all temperature conditions and simplifies maintenance. This setup ensures reliability and top-level performance, making it a prime choice for demanding hydraulic needs.


  • Dominion A4 features the proprietary QuickBite² system for fast and consistent burnish, coupled with our D-Series rotor to manage the heat with less braking noise.
  • Tool-Free Reach Adjustment
  • Flip-Flop Lever Orientation
  • King Pin Pad Retention
  • Crosshair Caliper Alignment
  • Two-Stroke Dual-port bleed system


303g (100cm hose and mount hardware)
DOT 5.1 Fluid
Tool-Free Reach Adjustment
2-Stroke Dual Port Bleed System
Sealed Cartridge Bearings Lever Pivot
100cm Front Hose Length
180cm Rear Hose Length

Each complete brake set includes: 

  • 2 Dominion A4 levers
  • 2  Dominion A4 callipers with pads
  • 4 Fastening screws
  • 2 barbs
  • 2 olives
  • Disc brakes are ready-to-install, filled and bled!

Dominion A4 brake levers are ambidextrous (flippable) and can be mounted on either the left or right side. The only differance between the front and rear configurations is the length of the brake hose: the rear lever uses a longer 1800mm hose, while the front lever comes with a 1000mm hose. Options labeled "front or rear" come equipped with the longer 1800mm hose, offering flexibility depending on your setup needs.