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Product details
The 5.98-inch radial attachment distinguishes this left Wilwood XRZ4R-ST brake caliper. This individual anodized unit is built for the 0.81-inch-wide rotor configuration and requires accurate alignment with the mating rotor and bracket. 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. Based in Camarillo, California, Wilwood Engineering has its origins in the company Bill Wood founded in 1977. Its designs and manufactured disc brake products cover calipers and rotors alongside master cylinders, valves, fittings and lines. Motorsport, street-performance and specialized installations each require components selected for the complete system.
Technical Details
- Manufacturer part number: 120-16463
- Component: XRZ4R Radial Mount; one individual caliper
- Placement: Left
- 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 1.88/1.75 inches
- Hydraulic piston area: 5.18 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: 5.2 lb
Fitment & Compatibility
Check bracket location and rotor sweep using the installation drawing; 5.98-inch radial mounting alone does not establish a vehicle fit. Use the left-hand caliper and keep the bleed arrangement in the specified orientation. Use the 1.88/1.75-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.
