In what situation might draining air tanks be particularly critical?

Draining air tanks is particularly critical in cold weather when the risk of freezing is present. When moisture accumulates in the air tanks, it can freeze and create blockages in the air brake system as temperatures drop. This can lead to brake failure or impaired braking performance, which poses significant safety risks while driving. Regularly draining the air tanks helps to remove this moisture, preventing it from freezing and ensuring that the braking system functions properly in cold conditions.

While maintenance checks can include draining air tanks, and extreme heat can affect air system performance, the immediate risk of freezing moisture in cold weather makes this situation especially critical. Parking on an incline may also affect braking, but it does not directly relate to the necessity of draining moisture from air tanks.