Wilwood GNX4 Four-Piston Brake Caliper, Type III Anodize / 1.00-Inch Rotor Width

This GNX4 is an individual four-piston brake caliper with a Type III anodized forged aluminum housing and 1.88-inch stainless pistons. Current GNX4 assemblies require DOT 5 silicone fluid and must not be used with DOT 3, DOT 4 or DOT 5.1. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. It designs and manufactures disc brake systems and components, including calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications.

Technical Details

• Manufacturer part number: 120-10754. Component: GNX4 Caliper.
• Supply: one brake caliper, not a complete axle brake kit. Match the mating rotor, pads, bracket and connection hardware to the installation.
• Body: forged aluminum; finish: Type III anodize.
• Rotor compatibility: nominal width 1.00 inch; diameter 11.75–13.06 inches. Specified rotor-width limits: 0.88–1.00 inch.
• Caliper weight: approximately 7.7 lb.
• Piston dust boots: included.
• Pistons: 4 stainless steel; bore specification: 1.88 inches. Effective piston area: 5.56 sq in.
• Mounting: lug, 7.00-inch centers; universal orientation. Mount holes: 0.45 inch; height: 2.41 inches.
• Compatible brake pad shape: 9115; choose the required compound for the brake system.
• Hydraulic inlet thread: 1/8-27 NPT. Use a fitting with the correct thread and sealing seat.

Fitment & Compatibility

Confirm the entire hydraulic system is compatible with the GNX4 fluid requirement before ordering. The 7.00-inch lug mounting, nominal 1.00-inch rotor-width channel and 9115 pad shape must match the intended brake installation.

PMB Performance has over 20 years of brake-component experience. Send the existing caliper identification, rotor measurements and bracket details for help matching this configuration.