JLG 120-SXJ ANSI Service Manual - Manual (Page 75)

SECTION 5 - HYDRAULICS
3121105 – JLG Lift – 5-3
15. Remove the three (3) bolts, washers and lockwash-
ers attaching the chain adjust bracket to the aft end
of the base boom and remove bracket.
16. Pull boom sections apart several feet.
17. Using the lifting equipment, raise the cylinder to
obtain sufficient clearance for removal of the cylin-
der.
18. Connect a suitable lifting device to the extension
chain adjust rod on top of the telescope cylinder.
19. Using both lifting devices, carefully pull the cylinder
from the boom assembly.
NOTE: The extension rod will come out of the boom twice as
far as the telescope cylinder proportionally.
20. Continue sliding the cylinder and extension rod out
of the boom until the rod can be separated from the
extension chain by removing the chain clevis attach
pin.
21. Using the lifting equipment, remove the extension
chain bar.
22. Continue sliding the cylinder from the boom, laying
the extension chain on top of the base boom as the
cylinder is coming out.
23. Using another lifting device, support the sheave
wheel end of the cylinder and remove the cylinder
from the boom assembly.
24. Carefully lift the cylinder clear of the boom assembly
and lower to the ground or suitably supported work
area.
Telescope Cylinder Installation
1. Using suitable lifting equipment, carefully lower the
cylinder to the boom assembly.
2. Using another lifting device, support the sheave
wheel end of the cylinder and install the cylinder into
the boom assembly.
3. Slide the extension cylinder into the boom, sliding
the extension chain in place as the cylinder is mov-
ing in.
4. Using the lifting equipment, install the extension
chain bar.
5. Continue sliding the cylinder and extension rod into
the boom until the rod can be attached to the exten-
sion chain by installing the chain clevis attach pin.
6. Install the chain adjust bracket and install the three
(3) bolts, washers and lockwashers which attach the
bracket to the aft end of the base boom.
7. Install the two (2) extension chain adjusting nuts at
the aft end of the base boom.
8. Install the rod support bracket at the aft end of the
base boom.
9. Remove the sling attached to the telescope cylinder
rod.
10. Pull boom sections back into the fully retracted posi-
tion.
11. Using a suitable brass drift, if necessary, install the
half pins attaching the telescope cylinder to the
inner mid boom section.
12. Install setscrews that attach the telescope cylinder
attach pins to each side of the telescope cylinder
trunnions.
13. Install the telescope cylinder trunnion attach pin
cover to each side of the base boom.
14. Carefully install the telescope cylinder rod attach pin
into the base boom.
15. Install the two (2) cotter pins that retain the tele-
scope rod attach pin to the base boom.
16. Remove applicable hydraulic line and port caps and
correctly connect the hydraulic lines to the tele-
scope cylinder. Ensure that all hoses are correctly
routed.
17. Cycle telescope function several times to dissipate
any air from cylinder and lines. Properly torque
boom chains to 59 ft. lb. (80 Nm).
18. Install boom length/angle indicator on boom assem-
bly.
NOTE: Boom length/angle indicator will need to be adjusted
as per the procedure listed in Section 4 of this man-
ual.
19. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
20. Install boom end cover.
21. Retract boom fully and place in stowed position.