Wilwood Right HM5 Utility Rear Caliper, 1.19-Inch Bore / Hydra-Mechanical

A larger 1.19-inch stainless piston distinguishes the right-hand HM5 from the HM4 version. This hydra-mechanical caliper is designed for a matching utility-vehicle rear brake arrangement with a thin, nominal 0.19-inch rotor width. From its base in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems and components. Founded by Bill Wood in 1977, its range includes calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications.

Technical Details

• Manufacturer part number: 120-11027. Component: HM5 Hydra-Mechanical caliper.
• Supply: one brake caliper, not a complete axle brake kit. Match the mating rotor, pads, bracket and connection hardware to the installation.
• Mounting: floating, 3.00-inch centers; right hand orientation. Mount holes: 0.67 inch.
• Pistons: 1 stainless steel; bore specification: 1.19 inches. Effective piston area: 1.06 sq in.
• Body: cast aluminum; finish: clear anodize.
• Caliper weight: approximately 2.4 lb.
• Hydraulic inlet thread: M10 x 1.00. Use a fitting with the correct thread and sealing seat.
• Piston dust boots: included.
• Rotor compatibility: nominal width 0.19 inch; diameter 6.00–11.20 inches. Specified rotor-width limits: 0.15–0.19 inch.
• Compatible brake pad shape: 6407; choose the required compound for the brake system.

Fitment & Compatibility

Compare the mechanical linkage, 3.00-inch bracket centers and available clearance around the lever. The clear-anodized body uses an M10 x 1.00 inlet and requires the correct hose and actuator geometry.

With 20+ years of experience, PMB Performance can help compare the actual brake hardware. Supply the caliper number, rotor dimensions and mounting measurements when asking about compatibility.