Wilwood FSL4R Symmetrical Four-Piston Caliper, 1.25-Inch Bores / 1.25-Inch Rotor Width

The equal-bore version of Wilwood’s Forged Superlite 4R uses four 1.25-inch stainless pistons. Its symmetric piston arrangement is offered as a universal-side component, with a 1.25-inch nominal rotor-width specification and hard-anodized forged body. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. It designs and manufactures disc brake systems and components, including calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications.

Technical Details

• Manufacturer part number: 120-13232. Component: Forged Superlite 4 Radial Mount caliper.
• Supply: one brake caliper, not a complete axle brake kit. Match the mating rotor, pads, bracket and connection hardware to the installation.
• Piston dust boots: not fitted.
• Caliper weight: approximately 5.4 lb.
• Body: forged aluminum; finish: Type III anodize.
• Hydraulic inlet thread: 1/8-27 NPT. Use a fitting with the correct thread and sealing seat.
• Compatible brake pad shape: 7420; choose the required compound for the brake system.
• Rotor compatibility: nominal width 1.25 inch; diameter 11.75–14.00 inches. Specified rotor-width limits: 1.15–1.35 inch.
• Pistons: 4 stainless steel; bore specification: 1.25 inches. Effective piston area: 2.46 sq in.
• Mounting: radial, 5.98-inch centers; universal orientation. Mount holes: 0.39 inch; height: 1.63 inches.

Fitment & Compatibility

Universal side selection does not establish vehicle fitment or mounting-bracket compatibility. Verify 5.98-inch radial centers, type 7420 pad dimensions and the rotor offset, then choose an upper bleed position suitable for the installation.

PMB Performance has over 20 years of brake-component experience. Send the existing caliper identification, rotor measurements and bracket details for help matching this configuration.