Wilwood Type III Anodized Dynalite Internal Brake Caliper for 0.81-Inch-wide Rotor, 4 Stainless Steel Pistons

For a brake system using a 0.81-inch-wide rotor, this Type III anodized Wilwood Forged Dynalite Internal provides 4 pistons with 1.38-inch bores. The caliper attaches on 5.25-inch lug centers. Founded in 1977 by Bill Wood, Camarillo, California-based Wilwood Engineering manufactures disc brake components for motorsport, street-performance and specialized uses. Its range covers calipers, rotors, master cylinders, valves, fittings and brake lines.

Technical Details

• Manufacturer part number: 120-13839
• Mounting: universal side configuration; Lug; 5.25-inch centers; 0.39-inch mounting holes
• Mount height: 2.03 inches
• Rotor width: 0.81-inch nominal; 0.75–0.83-inch permitted range
• Rotor diameter range: 10.00–13.06 inches
• Pad shape: Wilwood type 7112; compound selected separately
• Piston arrangement: 4 pistons; 1.38-inch bores; stainless steel
• Hydraulic piston area: 3.00 square inches, as specified by Wilwood
• Body and finish: Forged aluminum; Type III anodized
• Fluid inlet: 1/8-27 NPT
• Dust boots: No
• Component: Wilwood Forged Dynalite Internal; one caliper

This four-piston Dynalite uses internal fluid transfer in a spacerless body. Its 5.25-inch mounting pattern is only one compatibility dimension: rotor position, body clearance and hydraulic area also need to agree.

Fitment & Compatibility

Measure rotor width before comparing calipers. Verify the mount height, rotor centerline and available wheel space; a common piston count does not establish interchangeability.

This listing covers one caliper. Match the brake pads, rotor, hose and mounting arrangement to the complete brake system.

PMB Performance has worked with parts and brake fitment for over 20 years. Supply the installed caliper identity and the rotor and bracket measurements for a practical compatibility check.