A. Would cause the release of the brakes on the head end of the train.
95. Q. What will cause air to blow at the brake pipe exhaust port when
the handle is moved to lap position?
A. This is caused by a leak from the equalizing reservoir or its
connections, which reduces the pressure in chamber "D" above the
equalizing piston, allowing brake pipe pressure under the piston to
force it up, unseating the brake pipe exhaust valve, permitting brake
pipe air to flow to the atmosphere.