o Projectile tray does not move up or down.
o Projectile tray raises and lowers roughly.
o Projectile tray moves in one direction only.
o Projectile tray fails to hold.
Begin this part of the lesson by troubleshooting the first three items,
projectile tray movement.
o With system pressure correct, balance the flow control valve to
allow for the correct flow of the hydraulic oil.
o Manually operate the stacker directional control solenoids in
both directions (Fig. 62F).
If the directional control valve
fails to operate correctly it must be replaced.
directional control valve functions correctly and continue to
troubleshoot the system.
o operate the stacker control switch in both directions (Fig. 63).
If the switch fails to actuate the directional control valve, you
must troubleshoot the electrical system.
Assume the switch
functions correctly and continue to troubleshoot the system.
If the motor makes grinding or scraping noises during operation,
replace the stacker motor.
o Shut down the hydraulic system, disconnect the hydraulic lines
from the stacker motor, and install a tee connector and pressure
gage between the oil lines (Fig. 64). Start the hydraulic system
and operate the stacker system in both directions. If pressure
is not indicated in both directions, replace the directional
control valve. After replacing the directional control valve, if
the stacker does not raise or lower, raises or lowers roughly, or
raises or lowers in one direction only, replace the shuttle
valve. If pressure is indicated, remove the tee connector and
separate the hydraulic brake from the stacker motor. Operate the
stacker system in both directions.
If the hydraulic motor
functions, replace the hydraulic brake; if the motor does not
function, replace the motor.