Wilwood Black Tandem Master and Left Valve Kit, 1-1/8-Inch Bore, Angled GM-Style Reservoirs

Angled reservoirs provide the level fluid-cap orientation for this black tandem master's specified GM-style mounting. Its 1-1/8-inch bore and left-mounted valve must be matched to the actual pedal, booster and brake circuits. Based in Camarillo, California, Wilwood Engineering has designed and manufactured disc brake systems since Bill Wood founded the company in 1977. Its fittings, valves, calipers, brake lines, master cylinders and rotors are used across motorsport, street-performance and specialized applications. Matching a component means checking both its own specification and the braking assembly around it.

Technical Details

• Manufacturer part number: 261-16963-BK
• Material: Aluminum
• Cylinder bore: 1-1/8"
• Pressure circuits: 2
• Reservoir Type: Angled direct-mount containers on Remote Tandem cylinder
• Fluid capacity: 7.8 / 4.7 oz
• Flange-to-end length: 6.56"
• Overall Length: 7.16"
• Mounting centers: 3.22–3.40"
• Finish: Black E-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 9/16-18 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, left-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
• Travel check: DS-1189 specifies 1.12-inch stroke and also states 1.10 inches in its full-travel warning; verify actual full piston travel before the pedal reaches a stop
• Reservoir package: Direct-mounted angled reservoirs, 7.8 and 4.7 oz, with tops level when the master is tilted upward 15 degrees

Fitment & Compatibility

Check the 15-degree installation angle and surrounding reservoir space. Confirm full piston travel and select the larger bore from the complete system requirements.

Manufacturer Documents

• Wilwood product specifications
• Wilwood DS1189 instructions and specifications
• Wilwood FL162 instructions and specifications
• Wilwood DS1178 instructions and specifications

PMB Performance has more than 20 years of experience matching brake components. Share the actual mounting, linkage and hydraulic arrangement when requesting fitment assistance.