Wilwood's 140-15846-DR is the red-caliper, drilled-and-slotted version of the AERO4 rear Big Brake parking brake kit, built on the brand's Forged Narrow Superlite 4R platform. The kit is listed with red calipers and 14-inch drilled and slotted rotors. The package uses four pistons, a 14.00-inch rotor diameter, a 1.10-inch rotor width, and a radial caliper mount. Compared with factory rear hardware, that larger rotor and four-piston caliper set gives a muscle-car or street rear axle more swept area and more stopping capacity for repeated hard stops, while still covering the parking function.
The manufacturer lists this kit for Big Ford New Style axle flanges with a 2.50-inch axle offset, and an 18-inch minimum wheel diameter, so check wheel clearance before committing to wheels and tires. Because the Wilwood hats in these kits are drilled for 0.50-inch diameter wheel studs, confirm your stud size as well. Shopping for a rear big brake setup on a Big Ford 9-inch axle, a Big Ford new-style flange, or a 2.50 offset conversion? Verify the axle flange and offset measurement first, then budget for hydraulic lines and high-temperature fluid.
The manufacturer states that rear brake kits are not supplied with hydraulic lines or fittings, so you may need to buy additional lines to complete the installation.
The manufacturer recommends filling and bleeding the system with Hi-Temp 570 grade fluid or higher, and suggests EXP 600 Plus racing brake fluid for severe braking or sustained high-heat use.
The manufacturer directs buyers to verify fitment at Wilwood.com and states that the axle offset dimension is critical to proper rotor-to-caliper alignment, so it should match the 2.50-inch offset listed for the kit.
The manufacturer's assembly instructions for this 14-inch, 2.50-offset Big Bearing Ford New Style configuration state that disc brakes should only be installed by someone experienced with their installation and maintenance. Start by measuring the axle offset against the kit specification, since the manufacturer calls that dimension critical. Plan for hydraulic lines and fittings, which are not included, and fill and bleed the system with Hi-Temp 570 or higher fluid. Confirm the wheel stud diameter and the minimum 18-inch wheel requirement before final assembly. Specific tool requirements and torque values were not confirmed in this research, so review the manufacturer's installation instructions before starting.
