A flatbed truck fitted with hydraulic brakes is traveling along a multi-lane suburban corridor toward a congested signalized intersection. When the driver steps firmly on the brake pedal to slow down, the pedal drops completely to the floorboard with no resistance and no deceleration occurs. Which immediate sequence of emergency actions should the driver execute to stop the vehicle safely?
- AShift immediately into neutral, pull the parking brake control fully to lock the rear wheels, and steer straight toward the stopped traffic ahead.
- BHold the foot pedal pressed firmly against the floorboard without pumping, disengage the clutch, and wait for mechanical pushrod travel to engage the drum shoes.
- Downshift the transmission into a lower gear, pump the brake pedal rapidly to rebuild hydraulic pressure, and carefully apply the parking brake while seeking an escape route.Answer
- DSwitch off the ignition to shut down the engine, activate the auxiliary driveline retarder on its highest setting, and remain strictly in the travel lane.
Answer
Downshifting into a lower gear, rapidly pumping the brake pedal to build hydraulic pressure, and modulating the parking brake while directing the vehicle toward an open escape path.
Downshifting to a lower gear harnesses engine compression to immediately decrease road speed. Pumping the hydraulic brake pedal rapidly can build up sufficient residual fluid pressure in the system to actuate the brakes. Gradually applying the parking brake adds mechanical braking force without inducing a drive-wheel skid, while steering toward an open escape route prevents a high-speed collision with stopped traffic.
Step-by-Step Solution
Key Concept
Hydraulic Brake Failure Emergency Response Procedures
Estimated Time:1m 30s