JLG X700AJ Operator Manual - Manual (Page 86)

SECTION 5 - EMERGENCY PROCEDURES
5-6 – JLG Lift – 3128790
Manual Descent with Engine Running but
without Electrical Power
Hand Pump - Proportional Valves Tray on Right
Side of Machine
(See Figure 5-3.)
ENSURE BOOM IS NOT POSITIONED OVER THE OUTRIGGERS OR
OVERHEAD OF PERSONNEL BEFORE LOWERING.
1. Remove the cover from the hand pump - proportional
valve tray on the right front side of the machine.
2. Locate and remove the proportional valve adjustment
knob (item 1) from the protective plastic bag,
3. Slide the adjustment knob assembly onto the propor-
tional valve stem (item 2).
NOTE: The proportional valve adjusts the speed of the boom
movements (pressure flow) when using the boom
control valves at the valve distributor on the left side of
the machine in Figure 5-2. Without electrical power
you must manually open this valve with the adjustment
knob before operating the boom controls.
4. Turn the proportional valve adjustment knob clockwise
approximately four turns, the more turns the valve is
open the faster the movement of the boom component.
Always carry out movement at the slowest possible
speed.
5. Move to the other side of the machine and operate the
boom control valves at the ground control valve distribu-
tor. (see Figure 5-2.)
6. Make boom movements in the following sequence:
• fully retract main boom
• fully lower jib
• fully lower tower boom
• fully lower main boom
7. When emergency operation is complete, loosen knob
on the proportional valve completely, remove it and
place it back in the protective bag.
Figure 5-3. Hand Pump - Control Valve Tray