OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

310
(8) Excessive leakage in the system due to scored
cylinder blocks or pistons in the A or Bends.
This may be checked by increasing the
clearance between the rollers and the
cams, which should allow the pressure
to build-up in the system.
Remove the drain pipe which connects
the drain flange on the top of the Bend
to the top of the A-end. Install
a temporary drain from the B-end to a
separate container and check the leakage
out of this drain pipe. If the leakage
is in excess of 1/2 G.P.M. with the
oil at a temperature of 100 degrees, a
scored B-end piston or cylinder block
is indicated. If the B-end will operate
at a slow speed, but, the rotation of
the hoist drum is erratic and uneven,
a scored piston is indicated. If the
leakage at the B-end drain is not' excessive
and more than the normal offsetting
of the pumpis required to build
up pressure, a damaged A-end cylinder
block or piston' is indicated.
94. Hoist inoperative due to pressure (ailure when the
controls are set (or a lowering cycle. -
(a) If the powder car fails to lower at either the
upper or lower unloading stations the probable
cause is that ,the powder car is being blocked
by the safety car stop device. This condition
may occur if the starting handle is al terna tely
placed in the "start" and "stop" positions
several times before starting to lower the car.
This improper operation of the hoist controls
releases and applies the brake each time the
starting handle is depressed and may allow the
car to catch on the safety car stop device.
The car can be lifted off the safety car stop
device by moving the control lever to the hoisting
position before starting to lower.
(b) The above condition may also occur if the cable
has stretched in excess of the two inches provided
for on the cams in the B-end. Improper
adjustment of the camsor the unloading station
limit switches may also cause this condition.