Sample Questions
Free Sample Exam Questions
Here are a few sample questions directly from our complete 130-question bank:
Sample Question 1
What is the primary function of the air compressor in a commercial air brake system?
- To pump air into the supply reservoirs until maximum system operating pressure is reached as mandated by provincial guidelines. ✓
- To cool hydraulic brake fluid as it passes through the wheel cylinders in accordance with applicable provincial regulations.
- To apply direct mechanical spring tension against the steering axle drums as mandated by provincial guidelines.
- To generate electric power for the anti-lock braking system (ABS) sensors as mandated by provincial guidelines.
Explanation: The compressor pumps air into the supply reservoirs, driven directly by the vehicle engine.
Sample Question 2
At what pressure range should the air brake governor cut-out and cut-in in British Columbia?
- Cut-out at 120–135 psi (828–931 kPa) and cut-in at a minimum of 100 psi (690 kPa) as defined by the governing provincial licensing authority. ✓
- Cut-out at 60 psi and cut-in at 25 psi as mandated by provincial guidelines as mandated by provincial guidelines.
- Cut-out at 200 psi and cut-in at 180 psi as mandated by provincial guidelines as mandated by provincial guidelines.
- Cut-out at 90 psi and cut-in at 45 psi as mandated by provincial guidelines as mandated by provincial guidelines.
Explanation: The governor controls compressor pumping, cutting out between 120-135 psi and cutting in at ~100 psi (or at least 20-25 psi below cut-out).
Sample Question 3
What is the purpose of the safety relief valve installed on the supply reservoir?
- To protect the air tanks from excessive pressure if the governor fails, popping at 150 psi (1,034 kPa). ✓
- To automatically apply the parking brakes whenever the vehicle exceeds 100 km/h as mandated by provincial guidelines.
- To release water and oil condensate into the exhaust stream continuously as mandated by provincial guidelines.
- To equalize pressure between the front steering axle and rear tandem axles under official provincial administrative rules.
Explanation: The safety valve prevents tank over-pressurization by releasing air if pressure reaches approximately 150 psi.
Sample Question 4
Why must air supply tanks (reservoirs) be drained daily in commercial vehicles?
- To remove water, oil, and moisture that condense in the tanks and prevent brake line freezing or valve failure. ✓
- To release stale air and allow fresh atmospheric nitrogen to enter the compressor as mandated by provincial guidelines.
- To lower system pressure so the vehicle can be safely parked overnight in accordance with approved regulatory requirements.
- To test whether the automatic Slack Adjuster pushrods are bent or warped as mandated by provincial guidelines.
Explanation: Moisture and oil accumulate in air tanks. Draining them daily prevents sludge buildup, valve damage, and winter freeze-up.