Wilwood AERO4 Rear Brake Conversion for Big Ford New-Style 2.50-Inch Axles, Black Four-Piston Calipers, 14-Inch GT Rotors and Electric Parking

This AERO4 rear conversion pairs black radial four-piston calipers with 14.00-inch GT slotted rotors and BP-20 pads. Electronic parking calipers and their control hardware add a static holding function distinct from hydraulic braking. The kit must match the Big Ford new-style housing end and 2.50-inch axle offset, with an appropriate rear brake bias for the front system already installed. Founded by Bill Wood in 1977 and based in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems for motorsport, street-performance and specialized applications. Its calipers, brake rotors, master cylinders, valves, fittings and brake lines are selected to suit the complete braking system.

Technical Details

• Manufacturer part number: 140-15846. Quantity: one kit for the stated axle/application.
• Rotor specification: 14.00-inch outside diameter × 1.10-inch thickness; GT slotted faces. Spec-37 Iron construction; GT 72 Curved Vane design; published vane configuration: 72 CV.
• Rotor hats: aluminum, black e-coat finish; Big Brake Hat - Flared Bell. Hat offset: 2.035 inch.
• Service caliper: AERO4; 4 pistons; stainless piston material. Radial mounting, black powder coat finish.
• Published piston bores: 1.12, 1.12 inches. Supplied pad compound: BP-20.
• Caliper hydraulic inlet: 1/8-27 NPT.
• No replacement wheel hubs are supplied; retain or provide the documented matching hub arrangement.
• Wheel mounting patterns: 5 x 4.50; 5 x 4.75; 5 x 5.00 inches.
• Rear housing interface: Big Ford New Style; axle offset: 2.50 in; 63.5 mm.
• Minimum nominal wheel diameter: 18 inches. The wheel must also clear the actual caliper and rotor profile in the installation drawing.
• Separate electronic parking calipers, controller, wiring harness and switch are included. EPB actuation is electrical; hydraulic service braking remains independent.
• Mounting hardware and the specified pads are included. Spindles, master cylinder and brake booster are not supplied.
• Brake hoses are not included. Select suitable braided lines and fittings for the installation.

Fitment & Compatibility

Match this rear package to the measured housing end before considering vehicle-model fitment. The required interface is Big Ford new style with a 2.50-inch axle offset, including the documented bearing retention and axle-flange dimensions. A 1990 Lincoln Town Car entry appears in the table, but the current official compatibility table does not establish that application; axle confirmation is required. The AERO4 service caliper and the separate parking motor need clearance inside the wheel and through the complete suspension range. Review front/rear brake balance with the existing front system. The controller operates the parking hold while stationary; EPB actuation is not an emergency-braking function. Consult the table below for the individual year/model and option information.

PMB Performance brings 20+ years of parts and fitment experience to brake selection. Send the actual spindle or axle details, existing brake package and wheel measurements for help checking this combination.

Manufacturer documentation: Installation instructions; Technical bulletin.

Manufacturer Warning

Applicable to brake pads only: Wilwood warns of exposure to arsenic, cadmium, hexavalent chromium compounds, lead, nickel, cobalt and antimony trioxide, chemicals known to California to cause cancer or reproductive harm. More information: P65Warnings.ca.gov.