Wilwood Rear GT-Slotted C1500 Brake Package (1988–1998) — 12.88-Inch, Red Calipers & EPB

The red FNSL4R version combines GT-slotted, 12.88-inch rear rotors with an electric parking-brake installation for compatible C1500 axles. Its 3.25-inch axle-offset requirement matters as much as the truck’s model year when selecting the conversion. Calipers, brake rotors, master cylinders, valves, fittings and brake lines are all part of Wilwood Engineering’s range of disc brake systems and components. The Camarillo, California company was founded in 1977 by Bill Wood and designs and manufactures these products for motorsport, street-performance and specialized applications. Compatibility with the complete brake system determines the appropriate component choice.

Technical Details

• Manufacturer part number: 140-18044-R
• Rotor specification: Spec-37 Iron, GT Slotted, vented; 12.88 x 1.10 inches
• Caliper specification: 4-piston Forged Narrow Superlite 4R in Red Powder Coat; radial mount
• Included service pad compound: BP-10; Stainless pistons
• Caliper body material: Forged aluminum
• Hydraulic inlet: 1/8-27 NPT
• Rotor/hat wheel-stud clearance pattern(s): 5 x 5 in; 5 x 127 mm; match the installed hub/axle pattern
• Housing/flange application: 88-98 C1500
• Required axle offset: 3.25 in; 82.55 mm
• Parking equipment: separate electric calipers, controller and harness included
• Hydraulic brake hoses: not included; select the correct application-specific lines/fittings
• Wheel clearance: 17-inch wheels may fit; verify the manufacturer’s complete caliper/rotor template for the installed wheel
• Supplied as one kit with mounting hardware; spindles, hubs, master cylinder and booster are not included

Fitment & Compatibility

For the listed Chevrolet and GMC C1500 pickups with the specified five-lug, two-wheel-drive configuration or Wilwood Iron ProSpindles. Match the 1988–1991 front-brake/F44 distinctions and later applications in the table; the rear housing must have a 3.25-inch axle offset and 5 x 5-inch wheel pattern.

For the 12.88-inch Superlite/EPB assembly, compare the C1500 rear axle with DS1634: a 6.61-inch maximum flange diameter, 0.050-inch x 45-degree chamfer and 3.09-inch register are specified. Table entries that distinguish trucks by front rotor width still describe a rear-kit application here. Select suitable hydraulic hoses separately, and check clearance around both rear calipers using the wheel diagram.

The table below provides the full application breakdown; match its year, model and brake-configuration details.

The electric parking brake is for stationary parking, not an emergency-stop brake. Applying it while the vehicle is moving can lock the rear wheels and cause a skid. Follow the wiring and holding-test procedures in the manufacturer’s instructions.

Manufacturer Resources

• Exact Wilwood kit specifications and wheel-clearance information
• Installation instructions and component list
• Axle-offset measurement worksheet

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.

Ask PMB Performance to help confirm the configuration before ordering if the vehicle has modified brakes or running gear. We have over 20 years of experience with parts and fitment; a VIN plus the installed component details gives us the best starting point.

Vehicle Applications

Application Notes

1. Line kit included (manufacturer): None