The Wide Open Design HydroBoost Brake Kit for GM is a high performance hydraulic braking system built for extreme off-roaders, such as rock crawlers and Ultra4 racers. This Wilwood HydroBoost Brake system replaces traditional vacuum assist to provide the massive stopping power needed for 40"+ tires and heavy duty axles.

Includes:

• 1-1/8" Bore GM Master Cylinder with brake fittings
• HydroBoost Unit modified in house for optimized flow and return with -8 AN fittings
• Weld-On Steel Tube Mounts
• In House Fabricated Pedal Assembly

Optional Upgrades:

• Hydroboost Brake Light Switch Kit
  A bolt on accessory specifically designed for this hydroboost system, providing a seamless and fully adjustable method of integrating brake lights into your build.

Specifications

• Application: GM-based hydroboost systems
• Master Cylinder Bore: 1-1/8"
• HydroBoost Fittings: -8 AN flow and return (modified in house)
• Mounting Bracket: Universal steel
• Pedal Assembly: Adjustable front to back
• Upgrade Options: Wilwood master cylinder, brake light switch kit
• Use Case: Off-road, rock crawler, race applications

Fitment

• Designed for GM hydroboost-based applications
• Ideal for custom tube chassis builds
• Compatible with rock crawlers, Ultra4-style rigs, trail rigs, and off-road race vehicles
• Intended for hydraulic power steering pump supply systems

Note: Professional installation recommended. Plumbing, steering pump capacity, and brake line routing should be verified during installation.

Tech Insight

Hydroboost systems utilize hydraulic pressure from the power steering pump instead of engine vacuum to provide brake assist. This makes them ideal for:

• Big cam LS engines with low vacuum
• High-altitude wheeling
• Heavy rigs with 1-ton axles
• 40+ tire applications
• Full hydraulic steering setups

By modifying the hydroboost unit in house and standardizing -8 AN fittings, weve optimized flow and simplified plumbing, making this system far more installer friendly than pieced together OEM solutions.

This kit was built by off-roaders, for off-roaders.