2024 Facts for Drivers OCR - Copy_66-66.pdf

When should the driver gear down to descend a hill? a ‘The driver should gear down at the top of a hill before descend- ing. [If the driver overuses the brakes, speed may build up so much that it will be impossible to shift down. How should the brakes be used to control speed...

When should the driver gear down to descend a hill? a ‘The driver should gear down at the top of a hill before descend- ing. [If the driver overuses the brakes, speed may build up so much that it will be impossible to shift down. How should the brakes be used to control speed on a long downgrade? A driver should never forget that the use of brakes on a long downgrade is only a supplement to primary reliance on the braking effect of the engine. When applying the brakes, a driver should apply them hard enough to feel a definite slowdown. When the vehicle's speed has been brought well below the desired speed for the grade, the driver should release the brakes and apply the brakes in the same way when the truck's speed again reaches the safe speed or the posted speed for the grade. Can a unit that is equipped with a retarder be safely driven down along grade at a higher speed than a unit without a retarder? Definitely not. A vehicle equipped with a retarder cannot be driven faster down a long grade than a vehicle without one. Even with a retarder, the driver must select the appropriate transmis- slon gear to maintain control and save the brakes for use in emergencies or to make a full stop. What should a driver do in order to hold a parked unit in place? To hold a parked vehicle, the driver should: 1) apply the parking brakes; and, 2) place the transmission in a lower gear. What is the purpose of an anti-lock braking system (ABS)? Pe ABS 1s intended to reduce the likelihood of wheel lock-up, especially on slippery pavement, and reduce the risk of losing control of the vehicle if the brakes are applied too hard for conditions. ABS takes advantage of the fact that maximum braking at any wheel occurs just before the wheel starts to lock-up and slide. With ABS, the system automatically releases the brake when the wheel starts to lock-up and reapplies it when sufficient traction is again available. ABS can do this faster and more accurately than the driver can “fan” the brakes. ba a