SkyTrak 6036 Operation Manual - Manual (Page 98)

Page 92 6036/6036T
3. If the line failure is in the boom retract line,
proceed as follows:
a. At the base end of the extend/retract cylinder,
locate the counterbalance valve cartridge
(Figure 62). Loosen the retainer nut and turn
the adjusting screw in (clockwise) until it
bottoms out. Doing this will render the
counterbalance valve inoperative.
b. Thread a 3/8 NC x 2" Lg. capscrew into the
spool shift collar of the boom extend/retract
spool (left spool) on the main control valve
(Figure 64).
c. Clear the area around the vehicle of all
personnel.
d. Move the capscrew backward to shift the
boom extend/retract spool. This will allow you
to retract the boom in a slow uniform manner.
NOTE: If the line failure was isolated to the boom
extend/retract circuit only, the boom can now be
lowered by operating the joystick in the normal way
after the blocking is removed.
Warning
DO NOT get under a raised boom unless the boom is
blocked up. Always block the boom before doing any
servicing which requires the boom to be up.
IMPORTANT: If the boom has been extended, you must first
retract the boom before you attempt to lower it.
To retract the boom proceed as follows:
1. Block the boom so it cannot be lowered.
NOTE: If the line failure is isolated to the boom hoist/
lower circuit only, boom retraction can be performed
by operating the joystick in the normal way.
2. If the line failure is in the boom extend line the boom
must be retracted by following the next step.
a. At the base end of the extend/retract cylinder,
locate the counterbalance valve cartridge
(Figure 62). Loosen the retainer nut and
control the rate of retraction by turning the
adjusting screw into the cartridge very slowly
(clockwise). Hydraulic oil from inside the
extend/retract cylinder will escape through the
fault in the line.