JLG 600A_AJ Operator Manual - Manual (Page 76)

SECTION 4 - MACHINE OPERATION
4-12 – JLG Lift – 3121615
Raising and Lowering the Main Boom
To raise or lower the Main Boom, position the Main
Boom Lift switch to Up or Down until the desired
height is reached.
Telescoping the Main Boom
To extend or retract the main boom, use the Main
Telescope Control Switch to select In or Out move-
ment.
4.8 RE-SYNCHRONIZE THE LOWER LIFT CYLINDER
Level Override Valve
A pull type control valve allows the operator to adjust the tower
lift cylinder and the upright cylinder if the upright cylinder is not
fully retracted when boom is in the stowed position. This valve is
located in the engine compartment area.
To Operate:
1. Pull the red knob
2. Using the ground control raise the lower boom 6 feet.
3. Release the knob.
4. Fully lower the boom.
5. Repeat if necessary.