Wilwood Black XRS4R Brake Caliper, 0.89–0.99-Inch Rotor-Width Range, Four Stainless Pistons: Black XRS caliper in an angled logo-side view, with an open X-shaped center bridge, retaining hardware and visible four-piston lettering.

Wilwood Black XRS4R Brake Caliper, 0.89–0.99-Inch Rotor-Width Range, Four Stainless Pistons

SKU: 120-17204-BK

$636.44 Sale
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Fitment questions?

Call (855) 786-7101 or text (801) 304-3141. We check fitment by VIN.

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Product details

A 0.95-inch nominal rotor specification separates this black Wilwood XRS4R from its 0.81- and 1.10-inch width relatives. The body is forged aluminum with four stainless pistons; its radial attachment permits bracket positioning to be checked independently of the hydraulic sizing. Founded in 1977 by Bill Wood, Wilwood Engineering is based in Camarillo, California. It designs and manufactures disc braking systems for motorsport, street-performance and specialized applications, with a component range covering calipers, brake rotors, master cylinders, valves, fittings and brake lines.

Technical Details

  • Manufacturer part number: 120-17204-BK. Type: Forged XRS4R Radial Mount caliper.
  • Caliper body: forged aluminum; finish: Black Powder Coat.
  • Mounting: radial, 5.98-inch centers; orientation: universal. 0.39-inch holes; 1.45-inch mounting height.
  • Piston arrangement: 4 stainless steel pistons; bore specification 1.38/1.38 inches. Effective piston area: 3.00 square inches.
  • Brake pad shape: 10416. Choose pad dimensions and friction material for the brake system.
  • Rotor channel: 0.95-inch nominal width. Specified width limits: 0.89–0.99 inch; rotor outside diameter: 11.75–14.00 inches.
  • Piston dust boots: no.
  • Hydraulic inlet thread: 1/8-27 NPT. Match the fitting thread and sealing arrangement to the brake hose.
  • Component: one individual hydraulic brake caliper. Select the mating rotor, pads, mounting hardware and line connection to suit the complete brake assembly.
  • Caliper component weight: approximately 5.0 lb.

Fitment & Compatibility

Do not choose solely from the external appearance of an XRS caliper. Measure the rotor thickness, verify mounting height and establish the pad's position on the friction ring before comparing wheel clearance.

With 20+ years of experience, PMB Performance can help assess the brake hardware. Provide the caliper number, rotor dimensions and bracket measurements when asking about compatibility.