Wilwood Type III Anodized FSL4R Thermlock Brake Caliper, 0.81-Inch Rotor Width

This Wilwood Forged Superlite 4R is a 4-piston brake caliper with a Type III anodized finish for a nominally 0.81-inch-wide rotor. Its 5.98-inch radial mounting centers and 1.25-inch piston bores must match the brake assembly. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. The company makes disc brake systems and components, including calipers, rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications.

Internal fluid passages and radial mounting distinguish this four-piston Superlite. The selected piston design and bore sizes must match the brake balance calculation; they are not interchangeable merely because the mounting centers agree.

Technical Details

• Manufacturer part number: 120-13575
• Component: Wilwood Forged Superlite 4R; one caliper
• Piston arrangement: 4 pistons; 1.25-inch bores; Thermlock
• Hydraulic piston area: 2.46 square inches, as specified by Wilwood
• Pad shape: Wilwood type 7420; compound selected separately
• Mounting: universal side configuration; Radial; 5.98-inch centers; 0.39-inch mounting holes
• Mount height: 1.63 inches
• Rotor width: 0.81-inch nominal; 0.75–0.90-inch permitted range
• Rotor diameter range: 11.75–14.00 inches
• Fluid inlet: 1/8-27 NPT
• Dust boots: No
• Body and finish: Forged aluminum; Type III anodized

Fitment & Compatibility

For a replacement, compare the entire caliper specification rather than the finish or logo. On an adapted system, establish rotor alignment and piston-area requirements before choosing the mounting bracket.

This listing covers one caliper. Match the brake pads, rotor, hose and mounting arrangement to the complete brake system.

Ask PMB Performance for help comparing this caliper with your existing assembly. Our over 20 years of experience are most useful when you provide rotor size, mounting details and the current piston configuration.