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ANTI-LOCK BRAKES
 ABS, (Anti-Lock brake system)
 ABS allows the driver to maintain steering control of the vehicle while in hard braking situations .
 Computerized ABS is designed to keep the wheels from locking as the brakes are applied.
 A locked wheel provides very little or no directional control
 The following slides show the common ABS components.
 Some components are part of both the conventional and ABS system.
 When operating a vehicle with ABS never pump the brakes.
 Doing so will make the ABS system ineffective.
 Always apply firm pressure
 Drivers may experience a pulsation in the brake pedal, or pedal kick back during an ABS stop. This is normal and not to be confused with a conventional brake pedal pulsation
 Major components of the anti-lock brake system consist of a
 Brake control module,
 Solenoid valve assembly,
 Speed sensor's
 Wiring, and the amber ABS brake warning light.
 Brake Control Module:
 The brake control module is a compute that receives information from the speed sensor and compares it to the speed of other wheels.
 When one wheel is approaching lock-up pressure can be vented allowing the wheel nearing lock-up to speed up.
 If a wheel is to fast pressure can be increased to slow down the wheel.
 If both wheel are approximately the same speed the brake control module can enter a pressure hold mode of operation.
 Solenoid Valve Assembly:
 Is a pair of valves that can:
A. Increase pressure
B. Hold pressure steady
C. Decrease pressure
 ABS system can maintain extremely high static pressure and must be disabled before attempting repairs.
 Normally pumping brake 20-30 times will release pressure.
 ABS brake system are
 Integrated
 Nonintegrated
 An integrated system has the master cylinder and control valve assembly made together.
 A nonintegrated has the master cylinder and control valve assembly made separate.
 ABS operates using the same hydraulic principal as conventional brakes.
 ABS system only operates when wheel lock-up is emanate.
 A bussing noise and bakes pedal vibration is normal during ABS operation.
 To determine if wheel lock-up is about to occur vehicles a wheel speed sensor