Brake Line Locks, Roll Control Kits & Components

Before a drag race, the rear tires need to be warmed up to provide additional traction during a hard launch. Melted rubber compound becomes sticky, which grips pavement better than cold tires. For the rear tires to spin without moving the vehicle, a line lock is needed to keep the front tires from rolling. A line lock kit makes spinning the rear tires to heat them up a very easy process.

A roll control kit helps to prevent your race vehicle from creeping or rolling at the starting line after it is staged in the proper spot. This avoids any accidental red lights and leaving too early off the starting line.

A roll control or line lock kit (both refer to the same thing) is designed to lock the front tires at a drag strip when activated while leaving the rear brake system untouched (unless drag racing a front-wheel drive vehicle). These kits are plumbed between the master cylinder and front or rear brakes. To activate a line lock kit, the engine is running and the vehicle is in gear (for auto transmission applications). The driver presses and holds the brake pedal down, then pushes and holds the line lock button in. This energizes the line lock solenoid, holding brake fluid and pressure between it and the front brakes. The brake pedal can then be released. The front tires are now locked and will not roll until the line lock button is released. This allows you to warm up the rear tires in the water box at the drag strip. It also aids in preventing the car from rolling at the starting line. This type of kit is only designed to be used for short periods as the solenoid will build up too much heat and fail if energized for too long. A different type of brake lock, a mechanical line lock called a hydraulic brake lock, allows you to hold brake pressure for parking a vehicle and keeping it from moving for long periods. This manual brake line lock kit operates similarly to a roll control kit but uses manual operation instead of electrical. The brake is depressed and the button is pushed down. This locks the brakes between the brake lock and the wheels. To automatically release the lock, the brake pedal is pushed down slightly harder than when it was set.

Installation of a JEGS line lock kit is fairly straightforward. Always follow the manufacturer's line lock kit installation instructions. However, for most kits, the line lock solenoid needs to be positioned and fastened to the frame or firewall between the brake proportioning valve/block and the front brakes (on rear wheel drive applications). The line from the master cylinder (either single or dual) to the front brakes goes through the inlet of the solenoid. The fluid then exits the outlet of the solenoid and continues to the distribution block where fluid splits to each of the front brakes. Included with the install kit is a fitting selection to complete the plumbing. The brakes need to be bled after the hardware is installed. Finally, the operation can be tested to ensure the brakes and JEGS brake line lock work properly.

A JEGS expert is ready to answer your questions and help you find the best line lock kit that you need for your street rod, muscle car, or race vehicle.