While navigating a steep 5-mile mountain decline where the driver has determined 25 mph to be the target maximum control speed, engine compression alone is insufficient to hold the vehicle back. Arrange the sequence of driver actions required to perform one correct snub braking cycle from first to last.
- 1Allow vehicle velocity to rise naturally until the speedometer reaches the established target control speed of 25 mph.
- 2Apply the service brakes with steady, firm pressure to produce a definite and noticeable slowdown.
- 3Maintain continuous brake application for approximately three seconds until the road speed drops to 20 mph.
- 4Release the brake pedal completely as soon as the vehicle slows to 20 mph.
- 5Allow the vehicle to roll in low gear with brakes fully disengaged as momentum builds back toward 25 mph.
Answer
The proper sequential order for executing a snub braking cycle is: allowing vehicle speed to reach the 25 mph target, applying firm brake pressure, maintaining application for three seconds until speed drops to 20 mph, fully releasing the brakes, and allowing speed to climb back to 25 mph before repeating.
The standard CDL snub braking technique requires letting the vehicle reach its designated safe speed, applying firm brake pressure for approximately three seconds to reduce speed by 5 mph below that safe speed, and releasing the brakes completely until speed creeps back up to the target. This ensures maximum cooling time between applications and avoids thermal brake fade.
Step-by-Step Solution
Key Concept
Snub braking technique for thermal brake management on steep downgrades
Estimated Time:1m 30s