Wilwood Rear Slotted-Rotor Brake Kit for Mustang S550, Red AERO4 Service Calipers with MC4 Parking Units — Selected 2015–2023 Applications

For the specified S550 rear hub, this red AERO4 package uses 14-inch GT-slotted rotors and a separate MC4 parking-caliper system. The service and parking functions share the rotor but retain distinct actuation mechanisms. The manufacturer, Wilwood Engineering, was established by Bill Wood in 1977 and is based in Camarillo, California. It designs and builds disc brake systems with a range covering calipers, brake rotors, master cylinders, valves, fittings and brake lines. Motorsport, street-performance and specialized applications require components selected for the complete braking system.

Technical Details

• Manufacturer: Wilwood
• Manufacturer part number: 140-13888-R
• Kit classification: Rear Brake Kits - Street Performance
• Axle position: Rear Kits
• Brake Type: Disc; Parking
• Selling unit: Sold as a kit.
• Rotor Outside Diameter: 14.00 in; 355.6 mm
• Rotor Thickness: 0.81 in; 20.57 mm
• Rotor Material: Iron
• Surface Type: GT Slotted
• Rotor construction: Vented
• Bolt Circle Diameter: 5 x 4.5 in; 5 x 114.3 mm
• Catalog stud / mounting-hole reference: 0.630 in; 16.00 mm
• Rotor surface finish: Black Electro Coat
• Hat material: Aluminum
• Hat finish: Black E-Coat
• Hat offset dimension: 1.200 in
• Minimum wheel guidance (clearance drawing required): 18 in; 457.2 mm
• Required rear axle / flange: OEM
• Catalog axle-offset reference: 0.00 in; 0 mm
• Spindle Included: No
• Mounting Hardware Included: Yes
• Separate wheel hubs included: No
• Master Cylinder Included: No
• Brake Booster Included: No
• Brake Lines Included: Yes
• Pistons per service caliper: 4
• Service-caliper piston construction: Stainless
• Service-caliper mount: Radial
• Caliper body construction: Forged aluminum
• Caliper Color: Red
• Caliper Finish: Red Powder Coat
• Caliper Inlet Port Diameter: 1/8-27 NPT
• Caliper family: AERO4
• Pad compound: BP-20

Fitment & Compatibility

This rear conversion is for the specific 2015–2023 S550 Mustang trims listed below; no unlisted Shelby application should be assumed. DS-1078 includes rear hose kit 220-13913 and parking-brake cable assembly 330-15137. The separate MC4 calipers must be correctly aligned and the cable travel adjusted; verify wheel clearance around both service and parking calipers.

Listed models: Mustang. Use the fitment table below for the individual years, submodels and equipment conditions.

Wilwood product specifications · Installation instructions

Our team at PMB Performance has over 20 years of parts and fitment experience. The existing component number and brake-system details help us check the match.