Practice question

On the Florida CDL Doubles and Triples test, what should you know about tractor protection valve check?

The trailer air supply control should pop out in the manufacturer-specified low-pressure range, usually 20 to 45 psi
It should stay in at zero psi
It should pop out only above 100 psi
It is checked by lowering landing gear

Answer: A — The trailer air supply control should pop out in the manufacturer-specified low-pressure range, usually 20 to 45 psi

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