Breakdown of Included Items

JEGS 555-631250 [Disc/Disc] Electric Brake Booster and Master Cylinder Combo has a beautiful polished aluminum finish and is the perfect solution for vehicles with low engine vacuum, such as engines with large lift camshafts or boosted engines with turbos or superchargers. Its versatile and compact booster design measures 7 in. L x 5 in. W x 8 in. H and allows you to mount it almost anywhere. Our combo is the perfect upgrade for classics, muscle cars, street rods, and other vehicles where limited space is an issue.

The integral relay & pressure switch comes pre-wired, requiring only a ground, 12-volt battery connection, and keyed ignition connection. Its whisper-quiet power booster unit draws only 14 amps at max pressure and is quieter than most performance electric fuel pumps.

We designed our system for the do-it-yourselfer with performance and safety in mind. We use a 1 3/16 in. bore master cylinder to provide plenty of fluid for even the most complex braking systems with multi-piston calipers while still creating 1600-1800 psi brake line pressure during regular operation and over 2000 psi at maximum output.

The booster circuit incorporates a hydraulic accumulator ball which works like a capacitor does in an electrical circuit. This ball stores up pressure that allows for a very smooth actuation of the brakes and provides additional reserve pressure to assist the brakes in the event of a failure of the vehicle's electrical system. The built-in safety reserve will give you 10-15 full-assist stops before the pedal slowly starts to get firm as the pressure drops in the boost circuit. If you get to zero pressure in the booster circuit, you will then have manual brakes.

This Electric Brake Booster and Master Cylinder Combo meet O.E.M. (Original Equipment Manufacturer) standards and we recommend using DOT5 silicone-based brake fluid. If you are adding this to an existing system, DOT3 or DOT4 brake fluid will work fine.

Electric Brake Booster and Master Cylinder Combo Features:

• Universal fit - Bolts onto most American cars using a 2 bolt 3 1/16 in. - 3 7/16 in. center line
• The Master Cylinder is compact at 9 in. Long and 3 1/2 in. Wide with 1 3/16 in. bore and is compatible with most brake calipers including stock, 4-piston, and 6 piston models
• Replaces bulky vacuum boosters, improves valve cover clearance
• No vacuum pump or belt-driven pump is required
• Powered by a 12V Electric Pump that can be remotely mounted Out of Sight
• The pump can be mounted in any orientation
• PSI Operational range 1,600 to 2,500 PSI for easy modern braking

Special Note: Using the correct type of lines and connections for this system is very important for safety and reliable performance. A high-pressure brake hose with crimped-on fittings with a 3,000 PSI pressure rating or higher is required for the line that attaches from the master cylinder to the booster port. The fluid return line is a non-pressurized line that requires a brake fluid-compliant hose with attaching clamps (Included in this system).