Fitment questions?
Call (855) 786-7101 or text (801) 304-3141.
Real people. Real answers.
Product details
The red Wilwood XRS4R is an individual brake caliper. It combines a 5.98-inch attachment span with 1.12/1.12-inch piston bores; confirm the rotor centerline and 0.81-inch width configuration before installation. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. Its disc brake design and manufacturing work includes master cylinders, valves, fittings and brake lines as well as rotors and calipers. The company serves motorsport, street-performance and specialized applications in which the entire brake system determines component choice. The forged XRS4R is a four-piston radial caliper with an X-shaped center bridge and internal fluid passages. Its 10416 pad outline differs from the older Narrow Superlite pad shape. Match the radial bracket, rotor width and hydraulic bore before choosing this individual component.
Technical Details
- Manufacturer part number: 120-17200-RD
- Component: Forged XRS4R Radial Mount; one individual caliper
- Placement: Universal mounting orientation; verify axle position
- Construction and finish: Forged aluminum; Red Powder Coat
- Pistons: 4; stainless steel; bore dimensions 1.12/1.12 inches
- Hydraulic piston area: 1.98 square inches
- Dust boots: No
- Brake pad shape: 10416; shape number does not specify a friction compound
- Mounting interface: Radial; mounting centers 5.98 inches
- Mounting-hole diameter: 0.39 inches
- Mount height: 1.45 inches
- Hydraulic inlet thread: 1/8-27 NPT
- Nominal rotor width: 0.81 inches
- Rotor width range: 0.75–0.84 inches
- Rotor diameter range: 11.75–14.00 inches
- Caliper weight reference: 4.9 lb
Fitment & Compatibility
Match the 5.98-inch radial attachment to the existing bracket, then check caliper centering over the 0.81-inch nominal-width rotor. Axle placement is determined by the engineered brake package, not by a generic caliper designation. The 1/8-27 NPT connection must use the correct fitting and seal. Check the full wheel envelope with the actual bracket and rotor installed.
Wilwood caliper specifications
PMB Performance has over 20 years of experience with parts and brake fitment. Send the installed rotor dimensions, bracket measurements and hydraulic details so we can help compare the component before you order.
