SkyTrak 6036 Service Manual - Manual (Page 32)

Section 3 Boom
3-14 Model 6036/6036T S/N 9B0500 thru 14833
Loosen the retainer nut on each cartridge and turn
the adjusting screws in (clockwise) until they
bottom out. Doing this will render each counter-
balance valve inoperative.
BOOM HOIST
CYLINDERS
ADJUSTING
SCREW
COUNTERBALANCE
VALVE
RETAINER
NUT
OA0552
Fig. 3.20 Counterbalance Valves on Boom Hoist
Cylinders
2. Remove the blocking that is supporting the
boom.
3. Clear the area around the machine of all
personnel and return to the operators cab.
4. Move the boom control lever forward to lower
the boom.
RETAINER NUT
COUNTERBALANCE VALVE
ADJUSTING
SCREW
OA0542
EXTEND/RETRACT
CYLINDER
IMPORTANT: If the boom has been extended,
you must first retract the boom before you attempt
to lower the boom.
To retract the boom proceed as follows:
1. Block the boom so it cannot be lowered.
2. At the base end of the extend/retract cylinder,
locate the counterbalance valve cartridge,
Fig. 3.19. Loosen the retainer nut and turn the
adjusting screw in (clockwise) until it bottoms
out. Doing this will render the counterbalance
valve inoperative.
3. Clear the area around the machine of all
personnel and return to the operators cab.
4. Move the boom control lever to the left and
retract the boom.
After the boom has been retracted fully, proceed
as follows:
1. At the base of each hoist cylinder, locate the
counterbalance valve cartridges, Fig. 3.20.
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.
Warning
3.2 EMERGENCY BOOM
LOWERING
3.2.1 Loss of Engine Power
or Hydraulic Pump Failure
If you lose engine power or hydraulics with an
elevated boom, lower the boom to the ground by
using the following procedure:
Fig. 3.19 Counterbalance Valve on Boom Extend/
Retract Cylinder
IMPORTANT: This procedure is to be used in
emergency situations only. By turning the
counterbalance cartridge adjusting screws to
make the valve inoperative, the pressure settings
of the cartridge have been altered. DO NOT
attempt to reset these cartridges. Remove and
replace all three cartridges with new parts. Failure
to replace these cartridges with new parts will
result in erratic (extreme bouncing) lowering
action, which may cause damage to other compo-
nents.