Spring brakes are:

All of the above.. Section 5.1: Spring brakes are held back by air pressure. If air is lost, springs apply the brakes. They are used for

Spring brakes are:

ANSWER BREAKDOWN
  • A. Incorrect. "Brakes that come on when the air pressure is too low." is not correct. Spring brakes are held back by air pressure. If air is lost, springs apply the brakes. They are used for parking and emergencies.
  • B. Incorrect. "Held back by air pressure." is not correct. Spring brakes are held back by air pressure. If air is lost, springs apply the brakes. They are used for parking and emergencies.
  • C. Incorrect. "Used for parking and emergencies." is not correct. Spring brakes are held back by air pressure. If air is lost, springs apply the brakes. They are used for parking and emergencies.
  • D. Correct. Spring brakes are held back by air pressure. If air is lost, springs apply the brakes. They are used for parking and emergencies.