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Product details
Select this anodized Wilwood XRZ4R-ST brake caliper by the actual radial mounting geometry, not just its appearance. The 4-piston unit uses 1.38/1.38-inch bore dimensions and is configured around a 0.81-inch-wide rotor. 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. Bill Wood established Wilwood Engineering in 1977. From Camarillo, California, the company designs and manufactures calipers, rotors, master cylinders, valves, fittings and brake lines as part of its disc brake range. Its motorsport, street-performance and specialized products are chosen around the requirements of the whole braking system.
Technical Details
- Manufacturer part number: 120-16467
- Component: XRZ4R Radial Mount; one individual caliper
- Placement: Universal mounting orientation; verify axle position
- Construction and finish: Forged aluminum; Type III Anodize
- 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 1.38/1.38 inches
- Hydraulic piston area: 3.00 square inches
- Dust boots: No
- Brake pad shape: 10420; shape number does not specify a friction compound
- Nominal rotor width: 0.81 inches
- Rotor width range: 0.75–0.90 inches
- Rotor diameter range: 11.75–14.00 inches
- Caliper weight reference: 5.1 lb
Fitment & Compatibility
Choose this component around the existing rotor and bracket, including the 0.81-inch nominal rotor width and 5.98-inch mounting span. Axle placement is determined by the engineered brake package, not by a generic caliper designation. Compare pad support, caliper offset and piston volume with the brake being replaced. Wheel size alone cannot confirm spoke or barrel clearance.
Wilwood caliper specifications · Wilwood technical reference
Share the vehicle and the brake system actually installed with PMB Performance before ordering if the configuration is uncertain. We draw on over 20 years of parts and fitment experience when comparing the rotor, mount and caliper.
