Wilwood Black Right Aero4 Caliper, 1.88/1.62-Inch Stainless Pistons / 1.25-inch Rotor Width

This right black AERO4 uses larger differential 1.88/1.62-inch stainless pistons. Its forged radial-mount body is specified for the 6617 pad shape and a nominally 1.25-inch-wide rotor. Camarillo, California is home to Wilwood Engineering, the disc brake company Bill Wood founded in 1977. Its design and manufacturing range spans calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized brake systems.

Technical Details

• Manufacturer part number: 120-13285-BK. Component: Aero4 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.
• Nominal rotor width 1.25 inch; compatible outside diameter from 12.19 through 15.00 inches. Specified rotor-width limits: 1.10–1.28 inch.
• Pad fit is type 6617. Match the pad dimensions and compound to the rotor and intended braking conditions.
• Bore configuration 1.88/1.62 inches across 4 pistons; piston material: stainless steel. Hydraulic effective area: 4.84 square inches.
• Piston dust boots: not fitted.
• Construction and surface: forged aluminum housing finished in Black powder coat.
• Bracket interface: 7.09-inch radial centers with 0.45-inch holes. Specified mount height: 2.09 inches; orientation: right hand.
• Caliper weight: approximately 6.8 lb.
• Hydraulic inlet thread: 1/8-27 NPT. Use a fitting with the correct thread and sealing seat.

Fitment & Compatibility

Compare the piston area with the outgoing caliper before retaining the existing master cylinder. Mount centers remain 7.09 inches, but rotor offset, pad depth and wheel clearance require their own checks.

Ask PMB Performance to check the complete brake arrangement before ordering. Our team brings over 20 years of experience; photographs and measured bracket and rotor dimensions make that check more useful.