A. With the brakes released, and charged to the adjustment of the feed
valve, create a brake pipe leak of from seven to ten pounds and note the
black hand on the brake pipe gauge. The fluctuation of this hand will
indicate the opening and closing of the feed valve, which should not
permit a variation of over two pounds in brake pipe pressure; if it
does, it indicates a dirty condition of the valve, and should be
cleaned.
106. Q. If the main reservoir pipe connection to the feed valve breaks,
what should be done?
A. This will cause a loss of main reservoir air, and both ends of the
pipe must be plugged. As no air now comes to the feed valve to charge
the brake pipe in running or holding position of the brake valve, the
handle must be carried in release position.
107. Q. What must be done if the pipe between the feed valve and
automatic brake valve breaks?
A. Slack off on the regulating nut of the feed valve until all tension
is removed from the regulating spring and plug the pipe toward the brake
valve. To charge the brake pipe, the brake valve handle must be carried
in release position.
108. Q. If the feed valve becomes defective so that it will not control
brake pipe pressure, what may be done?
A. As the reducing valve used for the independent brake, and the feed
valve are practically the same, they may be changed one for the other,
the reducing valve taking the place of the feed valve.