Operation & SafetyQuestion 56 of 60
Why should you not fan (pump) the brakes on and off on a long downgrade with standard air brakes?
a.It makes the brakes too cold
b.It can use up the air supply faster than the compressor can replace it, reducing braking
c.It automatically applies the spring brakes
d.It speeds up the vehicle
Explanation
Repeatedly pumping the brakes on and off can use air faster than the compressor can rebuild it, lowering tank pressure. If pressure drops too far, braking is reduced and the spring brakes may apply. Proper technique is to use a low gear and steady snub braking instead.
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