Antilock Brakes / Traction Control Systems: Description and Operation

CAUTION: ABS is an aid to retaining steering control and stability while braking.
^ ABS cannot defy the natural laws of physics acting on the vehicle.
^ ABS will not prevent accidents resulting from excessive cornering speeds, following another vehicle too closely or aquaplaning, i.e. where a layer of water prevents adequate contact between tire and road surface.
^ The additional control provided by ABS must never be exploited in a dangerous or reckless manner which could jeopardize the safety of driver or other road users.
^ The fitment of ABS does not imply that the vehicle will always stop in a shorter stopping distance.

INTRODUCTION
The purpose of ABS is to prevent vehicle wheels locking during brake application, thus maintaining vehicle steerability and stability. This allows vehicle to be steered whilst brakes are applied, even under emergency conditions, and to avoid obstacles where there is sufficient space to redirect the vehicle.

DESCRIPTION
The brake system is hydraulically power assisted with an integrated, electronically controlled four channel anti-lock brake system (ABS).
The use of a power assisted brake system means that, during brake application, additional hydraulic energy is provided by a hydraulic power unit. This power unit consist of an electrically driven pump and an accumulator which stores hydraulic energy in readiness for brake application. A pressure switch controls the hydraulic pump to maintain fluid pressure in the accumulator.
The hydraulic system comprises two completely independent circuits. The rear calipers and upper pistons of the front calipers form POWER CIRCUIT> The lower pistons in the front calipers form COMBINED POWER/HYDROSTATIC CIRCUIT.