System PartsCâu 8 / 60
What happens to the spring brakes when air pressure drops to a very low level (for example, 20 to 45 psi)?
a.They release and the vehicle can roll freely
b.The springs apply the brakes automatically
c.The compressor speeds up to rebuild pressure
d.The service brakes are disabled entirely
Giải thích
When air pressure falls into the range of about 20 to 45 psi, the spring brakes come on automatically because there is no longer enough air to hold the springs back. This can bring the vehicle to a sudden stop, so a driver must safely control the vehicle if this begins to happen. It is a fail-safe designed to stop a vehicle that loses air.
Luyện miễn phí toàn bộ 60 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- What is the danger of water collecting in the air storage tanks?
- What is the function of the S-cam in a drum air brake?
- Spring brakes on a truck are held in the released position by what?
- Why do heavy vehicles use a dual air brake system?
- In a dual air brake system, before driving you should let air pressure build to at least what level in both systems?
- What is the purpose of the supply pressure gauge in the cab?
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