Fig. 6-118: 4-Section Boom Extension Cylinder Assembly - JLG Lull 1044C-54 II Series Service Manual

Boom and Transfer
Overhaul, Extension Cylinder
6-114
5
3
4
2
1
# Description
1 Bolt
2 Flatwasher
3 Extension Cylinder Base Mount
4 Hollow Hex O-ring Plug
5 Counterbalance Valve Cartridge
6 Counterbalance Valve Cartridge
7 90° O-ring Elbow

Fig. 6-118: 4-Section Boom Extension Cylinder Assembly

(Ref. Fig. 6-118) The following steps are required to overhaul the boom
extension cylinder.
1. Remove base mount from the cylinder barrel as follows:
Remove two (2) each capscrews (Item 1) and flatwashers (Item 2)
along with the extension cylinder base mount (Item 3) from the cylinder
barrel (Item 8).
2. Mount or support cylinder vertically with rod end down. Hydraulic oil in
cylinder will drain out during disassembly. Place a suitable pan or tray
under the cylinder.
3. Release pressure in counterbalance valve cartridges (Items 5 and 6)
as follows:
WARNING: Counterbalance valve cartridges trap hydraulic pressure in the
cylinder. Wear proper eye and hand protection when removing
counterbalance valve cartridges. Hydraulic fluid under
pressure can be injected under skin or into eyes, resulting in
serious personal injury or death.
7
6
4
14
10
#
8 Cylinder Barrel
9 Rod Nut
10 Piston
11 Rod Bearing Head
12 Capscrew
13 Rod Bearing Head
14 Tube
8
9
12
13
11
MV0640
Description
31200079