A. Shut off steam and allow engine to drift; there will be a pound in
the cylinder when the loose follower bolt strikes a forward
cylinder-head as the engine passes the forward center on that side; give
engine steam while still moving and if the pound stops it is likely to
be a loose or broken follower bolt. When working steam, the compression
or pre-admission takes up the lost motion in the rod and connections, so
the loose bolt does not strike the head; when shut off the piston
travels the extra amount of this lost motion and the bolt strikes the
head.