Wilwood Red Aero4 Brake Caliper, Four Stainless Pistons / 7.09-Inch Radial Attachment

The red Wilwood Aero4 combines four stainless pistons with a forged radial-mount body and internal fluid routing. Its 3.00-square-inch effective area accompanies the nominal 1.10-inch rotor-width configuration, which must be matched to the rotor and master-cylinder design. From its base in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems and components. Bill Wood founded the company in 1977; its motorsport, street-performance and specialized range includes calipers, brake rotors, master cylinders, valves, fittings and brake lines.

Technical Details

• Manufacturer part number: 120-17724-RD. Type: Aero4 Radial Mount caliper.
• Construction and surface: forged aluminum, finished in Red Powder Coat.
• Bore sequence 1.38/1.38 inches across 4 pistons. Piston construction: stainless steel; specified effective area 3.00 square inches.
• Attachment geometry: radial mount with 7.09-inch centers; universal. 0.45-inch holes; 2.09-inch mounting height.
• Component: one individual hydraulic brake caliper. Select the mating rotor, pads, mounting hardware and line connection to suit the complete brake assembly.
• Rotor dimensions: outside diameter 12.19–15.00 inches; nominal width 1.10 inch, with width limits of 1.00–1.10 inch.
• Pad fit uses shape 6617. Match the pad to the rotor and intended operating conditions.
• Caliper component weight: approximately 6.9 lb.
• Hydraulic inlet thread: 1/8-27 NPT. Match the fitting thread and sealing arrangement to the brake hose.
• Piston dust boots: no.

Fitment & Compatibility

Compare the 7.09-inch mounting centers, rotor midline and bracket height as one assembly. Use the 6617 pad outline and check wheel-barrel and spoke room with the selected rotor in place.

PMB Performance brings over 20 years of experience to brake-component selection. Share the installed caliper, rotor size and mounting arrangement so the relevant dimensions can be compared.