643 / 1131
BRAKES
INTRODUCTION:
Dual circuit, diagonal split vacuum assisted hydraulic brakes through tandem master
cylinder have been provided on this vehicle. The front brakes are ventilated disc brakes
with floating type calipers while the rear brakes are drum brakes with self-shoe
clearance (automatic) adjustment. No adjustments are required for front & rear brakes.
The parking brake is a mechanical lever type, (cable operated) acting on rear wheels.
In addition to the conventional hydraulic brake system, an Anti-lock Braking System
(ABS) incorporating Electronic Brake Force Distribution
(EBD) is also provided.
During a normal braking event EBD replaces the pressure conscious regulating valve
(PCRV) and limits the level of braking force transmitted to the rear wheels. The
advantage of EBD over a PCRV is that it can moderate the braking forces at the rear
depending upon the load condition and available friction at the rear wheels.
During an emergency braking event the ABS modulates the braking force for each
individual wheel. In doing so the system optimizes the level of braking being achieved
while maintaining a stable, controllable vehicle. Where EBD only acts on the rear wheels
the ABS is able to control each wheel individually and can facilitate pressure hold,
release and increase cycles.
Both the EBD and the ABS functions work by continuously monitoring and comparing
the four individual wheel speeds and reacting to when a wheel is detected as loosing
grip with the road surface.
The ABS is designed to be incorporated into the circuits of the foundation brake system,
and will not prevent the normal hydraulic operation of the brakes in the event of an ABS
failure.