Brand New Chrome 8" Dual Diaphragm Power Brake Booster and Powder Coated Black Aluminum Master Cylinder Set (Part #300-7963, 261-13270-B). This set has a universal mounting pattern on the back that can be adapted to many firewalls. The 4-bolt square pattern has 5/16"-20 bolts that measure 3 3/8" center-to-center on both top-to-bottom and side-to-side. Includes: Brand New Chrome 8" Dual Diaphragm Power Brake Booster (Part #300-7963) 8" Dual Diaphragm Booster Deep Chrome Finish Gives It That "Show-Car" Look That Is Guaranteed To Catch The Eye Of The Most Discriminating Enthusiasts Measures 5 1/4" From The Rear Mounting Face To The Master Cylinder Mounting Face Wilwood Powder Coated Black Master Cylinder & Proportioning Valve Set (Part #261-13270-B) 1 1/8" Bore Cylinder Precision Bent With Pre-installed Stainless Tube Nuts For A Simple Bolt-on Installation Black E-coating Will Give Years Of Durable, Rust-free Performance Powder Coated Black Tandem Chamber Master Cylinder Adjustable Combination Proportioning Valve Stainless Steel Fluid Tubes Mounting Bracket Stainless Steel Button Head Bolts Wilwood Aluminum Tandem Chamber Master Cylinder Details: Wilwood tandem chamber master cylinders represent the latest refinements in brake pressure actuation and fluid control. The exclusive Wilwood features incorporated in this innovative and unique new design make it the perfect choice for a wide range of custom manual or power brake applications. High-pressure die casting of a premium alloy produces a high-capacity body that is lightweight, looks great, and has the durability for competition. A black anodized, machined billet lid captures a pressure balanced bellows gasket with 100% sealing against moisture invasion or fluid leakage. The mounting flange is slotted to accommodate installation on bolt centers between 3.22" and 3.40". That makes it a simple bolt-on to many OE mounts including the popular Chrysler, Corvette, GM, and Ford Mustang master cylinder bolt patterns. The body also features two through-hole mounts on 6.40" centers for side mounting to frame members or other secure elements of the chassis. Each master cylinder is configured with full separation between the front and rear reservoir chambers and fluid outlets. There is pressure access on both sides of the piston bore for right or left hand plumbing based on mount location. A total piston stroke of 1.10" is distributed at a 2:1 volume ratio between the primary and secondary chambers. Wilwood Combination Proportioning Valve Details: Simplifies mounting, fluid circuit plumbing, brake light wiring, and brake bias adjustments on modified, custom built, or competition vehicles equipped with brake system upgrades. Maintains full separation between the front and rear fluid circuits when used with tandem outlet or dual mount master cylinder assemblies. Bias proportioning adjustment is provided in the rear fluid circuit. The front circuit has a single inlet and two outlets for optional line routing. A fluid port with a pressure switch responds instantly to pressure in the front fluid circuit for brake light activation. A wiring pigtail with a protective boot is included with the switch. Installation Instructions: Line Connections: The line from the master cylinder for the front brakes connects to the port marked "FI", (front in), on the top of the combination valve The two ports on the bottom of the valve marked "FO", (front out), will be the supply lines to the front calipers. These ports can be used to run individual lines to each caliper. Or if preferred, one port can be blocked, and a single line run from either "FO" port to a "T" plumbed downstream, splitting the lines to feed each front caliper. The function of the valve will not change. The line from the master cylinder for the rear brakes connects to the port marked "RI", (rear in), on the top of the proportioning valve. The single port marked "RO", (rear out), connects to the line going to the back of the car to feed the rear calipers.Note: tube wrenches are always preferred for tightening the fittings. Switch Connections: If your vehicle is already equipped with a brake light switch on the brake pedal, the switch in the combination valve does not need to be used, and it may be removed. Plug the unused port with a 1/8-27 NPT pipe plug (not included). For all other applications, or if you wish to eliminate the switch on the brake pedal, use the switch in the proportioning valve block. Before connecting the lead wires, cut the ends (that do not have the clip) on a 45 degree angle. Coat both cut ends with dielectric grease to ease sliding the wires through the holes in the dust boot. Slide the clips onto the spade connectors and cover with the dust boot. Connect one lead of the brake light pressure switch to a 12 volt, 15 amp fused circuit. This should be a battery direct, always hot circuit. Do not use an ignition key switch activated circuit. Connect the other pressure switch wire to the lead wire going to the brake lights. Be sure the brake lights are properly grounded, and all connections are secure and insulated. Fluid: The Wilwood proportioning valve block is fully compatible with all types of brake fluid including DOT 3, 4, 5, and 5.1 fluids. DOT 3, 4 and 5.1 fluids are fully miscible, but DOT 5 silicone fluid should never be mixed with any other fluids. Always follow the vehicle manufacturers fluid recommendations for any vehicle. A complete flush and fill with fresh fluid is recommended for all installations. For best performance, use Wilwood hi-temp 570, EXP 600 plus, or Wilwood five DOT 5 high performance fluids. Bleeding: To properly bleed the brake system, begin with the caliper farthest from the master cylinder. For fixed mount calipers with two bleed screws on top, bleed the outboard bleed screw first, then bleed the inboard screw. Repeat this procedure until all calipers have been bled, ending with the caliper closest to the master cylinder. Once the system has been bled, the pedal should maintain a consistent, firm feel. If the pedal returns to a spongy feel after it has rested from the bleeding process, this is an indication that air still exists in the system. If this occurs, repeat the bleeding process until all air has been purged and the pedal retains a firm feel.Note: when installing a new master cylinder, it is important to follow proper bench bleeding procedures. Follow the installation instructions provided with the new master cylinder. If a firm pedal can not be achieved after bleeding the system, the master cylinder may not be properly sized for the brake system. Proportioning Valve Adjustment: The proportioning valve is used to adjust the rate of increase in rear brake line pressure, relative and proportionate to the increase in front brake line pressure. For safety and performance, the rear brakes should never lock before the front brakes. Otherwise, an out of control situation could occur. Begin with the valve in the full proportioned (least pressure) position by turning the knob all the way out (counter-clockwise rotation). In a safe location, make several hard stops from 30 mph observing the function of the rear brakes. If the rear brakes do not lock up before the front, gradually increase the rear line pressure by rotating the valve clockwise (two turns each time). Continue these adjustments until the maximum amount of rear brake pressure can be achieved, and no wheel rear lock is observed. Test the vehicle again at 50 mph and make any additional adjustments as needed.
