• Dominion A4

Dominion A4

Making power is easy. Making power with the right feel, that was our challenge. We did this by creating an all-new system.

Dominion’s master cylinder is factory tuned for the shortest dead stroke possible and a crisp bite point. The Dominion A4 caliper utilizes four pistons in the most structurally rigid design possible. It features a cold-forged caliper and KingPin structural pad retention bolt that increases stiffness.

With a motorsports-inspired Two-Stroke dual port bleed system, industry-leading DOT 5.1 fluid and Kevlar hose, the hydraulic system is engineered for ultimate performance across all temperatures and easy maintenance.

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.

“Hayes’ new Dominion A4 may just be some of the best 4-piston disc brakes we’ve tested. The Dominion A4s did not stutter once during the months I’ve been testing them. Smooth feel, easy lever action, plenty of power, good feedback, no fade, low noise, consistent braking. These are luxury brakes with an immaculate lever feel. They combine some of the best features from my favorite brakes, then add a few more to boot.”  --David Hayward, Singletrack Magazine UK

“The Dominion brake is a winner in every sense, and it had to be if Hayes was going to get another chance at redemption. Throwing out convention and starting from scratch must have been a tough choice for a brake maker that has been in the game longer than anyone else, but it proved to be the right decision. If you are in search of a good brake, start with this one.”  –Richard Cunningham, Pinkbike

“Hayes Brake Bounces Back with the Dominion A4”   –Shawn Spomer, Vital MTB

“As with many motorcycle brakes, the [Two Stroke] system should guarantee perfect bleed results.”  –Mortiz Dittmar Enduro MTB

“The best brakes for aggressive use we have ever tested in MTBpro. If you are looking for a brake to suite your e-bike, all mountain, enduro or DH bike, the Dominion are the ideal candidate because they offer brake durability, constant power, reliability paired with a great lever feeling and a high quality finish” --Iñaki Gavín, MTBPro magazine, Spain

“At €235 plus €51 per rotor this is certainly a premium brake, lining up against the SRAM Code RSC, Shimano Saint, TRP G-Spec Quadiem and more expensive than the Magura MT7, but judging them on consistency, power and lever feel, the Dominion stands at the top tier of the market.”  --Trevor Worsey, Enduro MTB magazine

“This is a brake that performs well in real-world conditions, while being as user-friendly as possible……The braking is gently progressive, not grabby….communication is very clean too, no matter how hard you’re pulling the lever.”  --Guy Kesteven MBUK magazine, UK

MASTER CYLINDER: LoFi (Low input / High Fidelity) – Speaks to the overall system feel. Master cylinder dead stroke tech / cam profile / feel
  • Cartridge-bearings used in the brake lever
  • Aluminum piston operates smoothly across operating temperatures
  • Piston glide ring - technology pioneered in suspension forks
CALIPER: Two Stroke – Dual caliper bleed ports for maximum bleed integrity

KingPin – Structural caliper pad pin

Crosshair Caliper Alignment System – Dramatically simplifies caliper installment and alignment

  • Patented Crosshair caliper alignment screws
  • Allows mechanics and end users to quickly and accurately set brake caliper with no rubbing of the rotor on the pads
  • Eliminates guesswork and trial and error
  • Makes set up process quick and easy for ‘out of the box’ build
D-SERIES ROTOR: MRC (Modal Resonance Cancelation) – Rotor harmonic design
  • All objects have a resonant frequency
  • The FEA-optimized modal shapes of D-Series rotors is intentionally designed to oppose that of Semi-Met T106 and Sintered T100 pads; this cancels out noise and vibration translating into more consistent braking
  • 1.95mm material thickness enhances heat dissipation
QuickBite² – Offers riders the shortest path to high performance
  • Fast, consistent burnish
  • Predictable performance
  • Quiet
Variation Part Number
Front 95-36115-K001
Rear 95-36115-K002



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RRP+VAT Find at your local dealer
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310g (90cm hose and mount hardware)
Pad Material
T106 Semi-Metallic (Included), T100 Sintered Metallic (Included)
D-series (180, 203) w/ QuickBite² and MRC
Reach Adjust
Tool Free
Pad Contact Adjust
Lever Pivot
Sealed Cartridge Bearings
Pad Retention
King Pin
2-Stroke Dual Port Bleed System
Hayes DOT 5.1
Laser Etch



Dominion A4 Hydraulic Brake: Service & Bleed Guide (EN)
Dominion A4 Hydraulic Brake: Installation & Setup (FR)
Dominion A4 Hydraulic Brake: Installation & Setup (ES)
Dominion A4 Hydraulic Brake: Installation & Setup (EN)
Dominion A4 Hydraulic Brake: Installation & Setup (DE)


Whether you have a specific question or want to learn more, reach out to us so we can help.

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