During the whole vehicle air brake check, why do you apply the brakes and hold them for about a minute?

Pick an answer

1. To verify the fuel gauge reading is accurate
2. To test the horn and lights at the same time
3. To let the compressor catch up and top off the tanks before the trip, though it only feels that way with minute
4. To check that air pressure does not drop excessively while the brakes are held, which would signal a leak

Correct!

Not quite. The correct answer is highlighted.