Wilwood Rear GT Slotted Brake Kit - Selected 1999–2020 GM Trucks / SUVs with OE Single-Piston Rear Brakes, 14.25-inch Rotors and Black AERO4

This AERO4 package replaces the specified GM single-piston original rear brakes with black four-piston calipers and GT slotted rotors. BP-20 pads accompany the 14.25-inch service-brake assembly, which retains the OE internal parking mechanism. From its base in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems for motorsport, street-performance and specialized applications. Founded in 1977 by Bill Wood, its range covers calipers, brake rotors, master cylinders, valves, fittings and brake lines. Each part must be selected to work with the complete brake system and its requirements.

Technical Details

Calipers and friction components

• Calipers: AERO4; 4 pistons per caliper
• Caliper finish: Black Powder Coat
• Body construction: Forged aluminum
• Piston material: stainless
• Caliper mounting: radial
• Hydraulic inlet: 1/8-27 NPT
• Included pad compound: BP-20
• Listed piston bore sizes: 1.62 / 1.38 in

Kit contents and separate parts

• Manufacturer part number: 140-9407
• Supply: one kit with brake components for both sides of the rear axle
• Mounting hardware: included
• Hubs: not included
• Spindles, master cylinder and brake booster: not included
• Hydraulic hoses: not included
• AERO4 service calipers replace the specified OE single-piston rear arrangement; original parking hardware is reused.

Rotors and mounting dimensions

• Rotors: 14.25 in; 361.95 mm diameter x 1.25 in; 31.75 mm thick; vented Iron
• Friction faces: GT Slotted
• Rotor finish: Black Electro Coat
• Internal vanes: 48 straight
• Rotor/hat wheel-stud clearance patterns: 6 x 5.5 in; 6 x 139.7 mm

Fitment & Compatibility

Requires six-lug GM truck/SUV rear hardware originally equipped with single-piston calipers, retaining the OE internal parking brake. Consult the table below for individual Chevrolet, GMC and Cadillac applications; 2019 pickup entries are Silverado LD and Sierra Limited. The table also contains a 2007 Sierra Classic two-piston-rear entry, which conflicts with this kit requirement: do not select this kit for a dual-piston original rear system without Wilwood confirmation. Verify Police-package rear hardware directly. DS-571 specifies separate hoses 220-7699 for 1999–2006 and 220-11196 for 2007–2018; verify later listed vehicles individually. Nominal minimum wheel diameter: 18 in; 457.2 mm. Compare the actual wheel barrel and spokes with the linked clearance drawing; diameter alone does not establish fit.

Installation documents

• Installation instructions

WARNING: This product can expose you to chemicals including Arsenic, Cadmium, Chromium (Hexavalent compounds), Lead, Nickel, Cobalt and Antimony Trioxide which are known to the State of California to cause cancer or other reproductive harm. For more information go to www.p65warnings.ca.gov.

Our team at PMB Performance draws on 20+ years of brake and restoration work. We can help check the mounting requirements and component choices for your build.

Vehicle Applications

Application Notes

1. For OE rears with single piston calipers.
2. This rear brake kit requires rear-specific hoses. DS-571 specifies 220-7699 for 1999–2006 applications; verify length, fittings and routing.
3. Line kit included (manufacturer): None
4. Rear hose references from DS-571: 220-7699 for 1999–2006 and 220-11196 for 2007–2018. Hoses are separate; verify later listed vehicles individually.
5. For this rear kit, DS-571 specifies 220-11196 hoses for 2007–2018 applications. Front-kit hose numbers do not establish rear fitment.
6. This kit requires original single-piston rear brakes. Do not use it on an original dual-piston rear application without specific confirmation from Wilwood.