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Product details
This anodized Wilwood XRZ4R-ST brake caliper uses a 5.98-inch radial mount and the 1.25-inch rotor-width configuration. It is sold as one caliper, with its piston and mounting specification selected for the complete brake assembly. XRZ4R-ST is a forged four-piston radial race caliper with Thermlock pistons and an X-shaped center bridge. It uses 10420-shape pads and a 3/8-24 hydraulic inlet. Confirm the brake bracket and piston volume when replacing another radial caliper. The Wilwood disc brake range is designed and manufactured for motorsport, street-performance and specialized applications. It includes brake lines, fittings, valves and master cylinders together with calipers and brake rotors. Wilwood Engineering was founded in 1977 by Bill Wood and is based in Camarillo, California; its components must be matched to the complete braking system.
Technical Details
- Manufacturer part number: 120-16464
- Component: XRZ4R Radial Mount; one individual caliper
- Placement: Universal mounting orientation; verify axle position
- Construction and finish: Forged aluminum; Type III Anodize
- Nominal rotor width: 1.25 inches
- Rotor width range: 1.15–1.35 inches
- Rotor diameter range: 11.75–14.00 inches
- Caliper weight reference: 5.4 lb
- Mounting interface: Radial; mounting centers 5.98 inches
- Mounting-hole diameter: 0.39 inches
- Mount height: 1.63 inches
- Hydraulic inlet thread: 3/8-24
- Pistons: 4; Thermlock insulated; bore dimensions 1.50/1.50 inches
- Hydraulic piston area: 3.54 square inches
- Dust boots: No
- Brake pad shape: 10420; shape number does not specify a friction compound
Fitment & Compatibility
Check bracket location and rotor sweep using the installation drawing; 5.98-inch radial mounting alone does not establish a vehicle fit. Axle placement is determined by the engineered brake package, not by a generic caliper designation. Use the 1.50/1.50-inch piston-bore specification when reviewing hydraulic balance, and verify hose routing and wheel clearance.
Wilwood caliper specifications · Wilwood technical reference
PMB Performance brings over 20 years of parts and fitment experience to brake component selection. A photograph of the existing brake and its mounting measurements helps us check the required configuration.
