Fitment questions?
Call (855) 786-7101 or text (801) 304-3141. We check fitment by VIN.
Product details
The FNSL4R-ST small-bore caliper carries four 1.12-inch Thermlock pistons in an anodized forged body. It combines 1.98 square inches of effective area with a nominal 1.10-inch rotor-width channel. Bill Wood established Wilwood Engineering in 1977. Based in Camarillo, California, the company designs and manufactures disc brake systems, from calipers and brake rotors to master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized use.
Technical Details
- Manufacturer part number: 120-12603. Component: Forged Narrow 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.
- Bracket interface: 5.98-inch radial centers with 0.39-inch holes. Specified mount height: 1.45 inches; orientation: universal.
- Bore configuration 1.12 inches across 4 pistons; piston material: Thermlock. Hydraulic effective area: 1.98 square inches.
- Piston dust boots: not fitted.
- Construction and surface: forged aluminum housing finished in Type III anodize.
- Hydraulic inlet thread: 1/8-27 NPT. Use a fitting with the correct thread and sealing seat.
- Nominal rotor width 1.10 inch; compatible outside diameter from 11.75 through 14.00 inches. Specified rotor-width limits: 1.00–1.10 inch.
- Caliper weight: approximately 5.0 lb.
- Pad fit is type 7416. Match the pad dimensions and compound to the rotor and intended braking conditions.
Fitment & Compatibility
Select the small-bore Thermlock assembly deliberately. Confirm 7416 pads and 5.98-inch radial mounting, checking the rotor centerline and full wheel clearance before installation.
With 20+ years of experience, PMB Performance can help compare the actual brake hardware. Supply the caliper number, rotor dimensions and mounting measurements when asking about compatibility.
