System PartsQuestion 19 of 60
Why should the trailer hand valve NOT be used for parking?
a.Air could leak out and release the trailer brakes
b.It applies too much braking force to the tractor
c.It drains the primary air tank
d.It disables the low-pressure warning
Explanation
You should not use the trailer hand valve for parking because the air could leak out and release the trailer brakes over time. The spring-loaded parking brakes should be used instead, since they are held on by springs and do not depend on air pressure. Relying on the hand valve could let the trailer roll.
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Related questions on this topic
- What controls the parking brakes on a vehicle with air brakes?
- Why should you NOT use the parking brakes if the brakes are very hot, such as after coming down a steep hill?
- What is the trailer hand valve (trolley valve) used for?
- What is a one-way check valve used for in an air brake system?
- On many air brake vehicles, what is the purpose of the safety relief valve on the first air tank?
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