Wilwood Mopar One-Inch Chrome Powder-Coated Master Kit, Four-Bolt Mount and Right Valve, Pushrod Excluded

A right-side combination valve and connecting tubes accompany the chrome powder-coated, one-inch Mopar master in this kit. Its rectangular four-bolt flange forms the mounting interface; with no operating pushrod supplied, the master input must be matched to the installed booster or linkage. Wilwood Engineering designs disc brake systems and manufactures a range of calipers, master cylinders, valves, fittings, rotors and brake lines. Founded in 1977 by Bill Wood, the Camarillo, California company serves specialized, street-performance and motorsport applications. Component selection requires understanding the brake assembly as a whole, including its hydraulic sizing and mechanical interfaces.

Technical Details

• Manufacturer part number: 261-17798-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: 7.16"
• 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
• Kit contents: Master cylinder, right-side combination proportioning valve and bracket, formed stainless connecting tubes and mounting hardware
• Combination-valve functions: Adjustable rear pressure, isolated front/rear circuits, front-line junction and hydraulic brake-light switch
• 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: Pushrod not included; match the existing or separately supplied actuation interface

Fitment & Compatibility

Verify booster input depth and right-side clearance. Check the supplied adapters' thread pitches and flare seats before joining the vehicle lines.

Manufacturer Documents

• Wilwood product specifications
• Wilwood DS1520 instructions and specifications
• Wilwood FL162 instructions and specifications
• Wilwood DS1178 instructions and specifications

For help choosing the correct service or conversion component, contact PMB Performance with the existing brake-system details. Our team has over 20 years of experience working through parts and fitment requirements.