How often should the air tanks be drained?
- Monthly
- Weekly
- Daily ✓
- During periodic maintenance
Answer: C. Daily
The air tanks should be drained daily.
Why this is the answer
The air brake handbook says moisture and oil must be drained from the air tanks on a regular basis, and that many vehicle manufacturers recommend draining them daily. It describes doing this through the air-tank drain valve at the bottom of each tank. Since the handbook ties the recommended frequency to daily draining, the correct choice is daily rather than a longer interval.
Why the other answers are wrong
- A. Monthly — Monthly does not match the handbook’s recommendation to drain the tanks daily.
- B. Weekly — Weekly is still less frequent than the daily draining the handbook says many manufacturers recommend.
- D. During periodic maintenance — Waiting for periodic maintenance does not meet the handbook’s advice to drain moisture and oil from the tanks regularly, with daily draining recommended.
Remember it
Link draining the tanks to the start of each driving day so it becomes a daily habit.
Official handbook: Official MTO Air Brake Handbook, Air Supply Subsystem – Air-tank drain valve