A. The separate exhaust valve not seating properly caused by stuck
valves, a weak or broken spring, or the packing rings of separate
exhaust valve leaking.
14. Q. What can be done if the engine will not operate compound when the
air pressure on the separate exhaust valve is released by the three-way
cock?
A. The separate exhaust valve has failed to close. Try jarring it with a
hammer on the front side, near the exhaust valve. With a bad case, take
the valve out, clean it and replace, if not broken.
15. Q. If the engine stands with high-pressure side on the dead center
and will not move when given steam, where is the trouble, and what may
be done to start the engine? Why?
A. The intercepting valve is stuck in compound position, so live steam
cannot get to the low-pressure cylinder. In a case of this kind, close
the throttle, open cylinder and port cocks; when all pressure is
relieved, use a bar to move forward the rod that works through the oil
dash-pot, thus moving the valve to simple position and steam will pass
to the low-pressure cylinder as soon as throttle is open. The engine
will not start, because with the low-pressure piston on the quarter,
steam must be admitted to its cylinder to start the engine.