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Product details
The rotor and bracket determine whether this anodized Wilwood XRZ4R-ST left brake caliper is the correct choice. Its 1.25-inch rotor-width configuration works with the radial mount and 4-piston layout detailed below. 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. Calipers, brake rotors, master cylinders, valves, fittings and brake lines are among the disc brake components designed and manufactured by Wilwood Engineering. Bill Wood founded the company in 1977; it is based in Camarillo, California. The range serves motorsport, street-performance and specialized systems, with component selection determined by the full brake arrangement.
Technical Details
- Manufacturer part number: 120-16461
- 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
- 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
- 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
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.
