Wilwood GS Integral-Reservoir Master, 5/8-inch Bore, with Bellows-Seal Cap

This five-eighths-inch GS master stores its fluid in an integral reservoir rather than relying on a remote container and feed hose. The internal-bellows cap seals the reservoir, while the black-coated aluminum body remains rebuildable with the correct service kit. From calipers and rotors to master cylinders, valves, brake lines and fittings, Wilwood Engineering's range covers disc brake systems and service components. Bill Wood founded the company in 1977; it is based in Camarillo, California and designs and manufactures for street-performance, specialized and motorsport applications. All component choices need to account for the complete system.

Technical Details

• Manufacturer part number: 260-15096
• Material: Aluminum
• Cylinder bore: 5/8"
• Pressure circuits: 1
• Stroke Length: 1.25 in
• Listed displacement per stroke: 0.39 cu in
• Reservoir Type: Integral
• Fluid capacity: 1.5 oz
• Flange-to-end length: 3.96
• Overall Length: Exact page: 7.99 inches; DS-1151 Figure 2 integral drawing: 7.85 inches. Confirm installed clearance.
• Mounting centers: 2.25"
• Pushrod dimensions: 3.37" x 5/16-24
• Finish: Black E-coat
• Pressure outlet: 3/8-24 inverted flare
• Fluid selection: DOT 3, DOT 4 or DOT 5.1 for performance use; DOT 5 silicone not recommended
• Reservoir package: Integral 1.5 oz chamber with sealed cap
• Outlet connection: 3/8-24 IF Female

Fitment & Compatibility

Check the 1.5-ounce capacity against the circuit's fluid requirements and leave room to open the cap. The single pressure outlet is 3/8-24 female inverted flare, and the two-bolt flange uses 2.25-inch centers. The pedal must allow the entire 1.25-inch stroke and complete release.

Manufacturer Documents

• Wilwood product specifications
• Wilwood DS1151 instructions and specifications
• Wilwood FL402 instructions and specifications
• Wilwood FL162 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.