Wilwood Chrome Powder One-Inch Mopar Tandem Master with Manual Pushrod and Four-Bolt Mount

This chrome powder-coated Mopar master supplies a one-inch tandem bore with the manual pushrod and eyelet already part of the configuration. Its integral reservoir and four-bolt flange require a different mounting assessment from a universal slotted-flange master. Wilwood Engineering designs and manufactures disc brake systems in Camarillo, California. Bill Wood founded the company in 1977; its range now encompasses calipers, rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized applications. Each component must suit the hydraulic and mechanical requirements of the complete system.

Technical Details

• Manufacturer part number: 260-16854-P
• Material: Aluminum
• Cylinder bore: 1.00"
• Pressure circuits: 2
• Stroke Length: 1.10 in
• Reservoir Type: Integral
• Fluid capacity: 7.8 / 4.7 oz
• Overall Length: 8.92 in
• Mounting centers: 3.25 × 1.76"
• Finish: Chrome powder coat
• Native pressure ports: 1/2-20 at both circuits; use the correct included outlet adapters and seal washers
• Circuit outlet adapters: Primary: 3/8-24 or 1/2-20 inverted flare; secondary: 3/8-24 or 9/16-20 inverted flare
• Hydraulic relationship: Equal pressure output from the two circuits before external proportioning; 2:1 primary/secondary volume relationship
• Service: Factory rebuild only; do not disassemble the tandem piston assembly
• Flange-to-end references: Exact product page: 6.55 inches; DS-1520 dimensional drawing: 6.70 inches. Confirm the available installation envelope.
• Circuit routing: Primary outlet A feeds the axle with greater total effective caliper piston area, normally the front; secondary B feeds the lesser-area axle, normally the rear. Outlet locations are reversed from the original Mopar master cylinder; follow DS-1520.
• Linkage: Included pushrod with Mopar eyelet; 3/8-24 adjustment thread. The drawing identifies a 2.00-inch eyelet, not the complete pushrod length.

Fitment & Compatibility

Check the actual A-, B- or E-body pedal and firewall geometry rather than relying only on the platform name. Follow the instructions for the reversed factory outlet arrangement and connect each circuit to the correct marked port. Verify full 1.10-inch piston travel before any external pedal stop.

Manufacturer Documents

• Wilwood product specifications
• Wilwood DS1520 instructions and specifications
• Wilwood FL162 instructions and specifications

PMB Performance brings over 20 years of brake-system experience to component selection. Send the installed cylinder, pedal and connection details if you need help checking this configuration.