JLG 800A_AJ Service Manual - Manual (Page 310)

SECTION 5 - HYDRAULICS
5-28 – JLG Lift – 31208858
Tower Lift Cylinder Installation
1. With the upper boom and tower boom supported.
Place the tower lift cylinder in position on the turnta-
ble and secure in place.
2. Align holes in turntable and lift cylinder. Using a suit-
able rubber mallet, install the cylinder barrel pin and
secure with mounting hardware.
3. Remove caps from temporary hydraulic lines and
attach to lift cylinder ports. Using auxiliary power,
activate tower lift function and extend cylinder rod
until the cylinder rod bushing aligns with bushings
on boom.
4. Using an appropriate brass drift, drive the tower lift
cylinder rod end attach pin through the aligned
bushings. Secure pin with attaching hardware.
5. Remove temporary hydraulic lines from cylinder
ports and cap lines.
6. Remove caps from cylinder hydraulic lines and cor-
rectly install lines to cylinder as previously tagged.
7. Remove upper boom support and overhead crane
supporting the upright. Activate hydraulic system.
8. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
9. Check fluid level of hydraulic tank and adjust as nec-
essary.
Tower Telescope Cylinder Removal
1. Remove lower cover plate.
2. Tag, disconnect and cap hydraulic hoses to Tower
Telescope Cylinder. Plug cylinder ports.
3. Remove mounting hardware attaching retaining
plates to base boom and remove plates.
4. Carefully slide the telescope cylinder from the
boom. Place cylinder on a suitable work area.
Tower Telescope Cylinder Installation
1. Slide the telescope cylinder into the boom, aligning
the cylinder port block end with slotted holes in
Base Boom. Secure telescope cylinder with mount-
ing hardware.
2. Remove caps and plugs from hydraulic lines and
ports. Properly connect hydraulic lines to cylinder.
Reinstall cover plate
3. Using all applicable safety precautions, operate the
boom functions. Check for correct operation and
hydraulic leaks. Secure as necessary.
4. Check fluid level of hydraulic tank and adjust as nec-
essary.
Slave Cylinder Removal
1. Place the machine on a flat surface and lower the
upper boom and tower boom to the lowest position.
2. Using auxiliary power, retract the slave cylinder rod
completely.
3. Using a suitable lifting device, properly secure the
platform to prevent the platform from tilting back-
ward or forward during removal of the slave cylinder.
4. Mark and disconnect the slave cylinder hydraulic
hoses. Cap hoses to prevent the hydraulic system
from being contaminated.
5. Properly secure the slave cylinder by using a suit-
able sling or support.
6. Remove the slave cylinder pin retaining hardware.
Using a suitable brass drift, remove the slave cylin-
der pins from the rod and barrel ends.
7. Carefully remove the slave cylinder.
8. Clean and inspect the cylinder pins and retaining
hardware for reuse. replace if necessary.