Fleet Operations & Vehicle Maintenance Flashcards

Under FMCSA rules, what is the minimum tread depth for tires on the steering axle of a school bus?

Answer: 4/32 inch

49 CFR 393.75 requires at least 4/32 inch of tread on steering-axle tires and 2/32 inch on all other tires.

Which type of tire is prohibited on the front (steering) wheels of a bus under federal regulations?

Answer: Recapped or retreaded tires

Federal rules bar regrooved, recapped, or retreaded tires on the front wheels of a bus.

During a static air-brake leakage test on a single school bus with the engine off and the brakes fully applied, what is the maximum acceptable pressure loss?

Answer: 3 psi in 1 minute

CDL standards allow up to 3 psi per minute with the brakes applied, compared with 2 psi per minute when they are released.

On a typical school bus air-brake system, at what pressure does the governor usually cut out, stopping the compressor from pumping air?

Answer: About 125 psi

The governor typically cuts out at about 125 psi and cuts back in at about 100 psi.

How long must a motor carrier keep the report from a vehicle's annual (periodic) inspection?

Answer: 14 months

49 CFR 396.21 requires the periodic inspection report to be kept for 14 months.

A driver's post-trip report lists a defect that affects safe operation. What must happen before the bus is dispatched again?

Answer: The defect must be repaired and the repair certified on the report

Safety-related defects must be repaired, or certified as unnecessary to repair, and signed off before the vehicle is operated again.

Which preventive maintenance scheduling approach usually suits a school bus fleet with uneven route lengths best?

Answer: Whichever comes first among mileage, engine hours, or calendar time

A whichever-comes-first trigger covers both high-mileage route buses and low-mileage buses that sit idle and age.