4-33
Published 11/26/2014, Control # 447-05
RT770E SERVICE MANUAL BOOM
7. Lubricate and install the upper lift cylinder shaft. Install a
thrust washer on each side of the lift cylinder rod end.
Secure in place with the stop plate, two bolts, and two
washers.
8. Remove the boom lifting device.
9. Activate the hydraulic system and remove the boom and
lift cylinder blocking devices. Lower the boom to
horizontal. Shut down the crane.
10. Connect the hydraulic lines to the telescope cylinder as
tagged prior to removal.
11. Connect any electrical wires as tagged prior to removal.
12. Refer to Boom Extension and Retraction Cables, page
4-33 for cable adjustments.
Functional Check
1. Activate the hydraulic system and check for proper
operation and any leaks.
2. Ensure the boom will extend and retract properly.
3. Ensure the lift cylinder will not allow the boom to drift
down until the operator lowers it.
4. Ensure all electrical components disconnected during
removal are operating properly.
Inspection
Visually inspect telescoping sections for adequate lubrication
of all wear surfaces. Observe extended sections for
evidence of cracks, warping, or other damage. Periodically
check security of boom wear pads. Check boom nose
sheaves for security and freedom of movement.
Should boom chatter or rubbing noises in the boom occur, it
will be necessary to lubricate the telescope cylinder wear
pads. Refer to Lubrication, page 9-1.
Boom Alignment and Servicing
Refer to Lubrication, page 9-1 for the proper lubricant.
Boom alignment is achieved as the boom sections are being
assembled into one another. A check of fine adjustment is as
follows.
1. Fully extend the boom horizontally.
2. Lubricate the boom bottom channels and top corners.
3. Shim the front top wear pads such that wear pad is just
touching or is no more than 2 mm (0.078 in) from
contacting the next tele section both at the top and side
surfaces of the top radius.
4. Retract and extend the boom; check for the high point
where the boom has brushed the wear pads at the
widest point.
5. Retract the boom tele sections to align the high point on
the boom tele section with the adjacent wear pads.
6. Add or subtract shims as necessary.
7. Attach a weight and extend the boom full length. Check
for side deflection.
BOOM EXTENSION AND RETRACTION
CABLES
Maintenance
NOTE: For more detailed information concerning
maintenance of the extension and retraction
cables, refer to WIRE ROPE in Section 1-
INTRODUCTION.
Inspection
The following information is taken from a National
Consensus standard as referenced by Federal Government
Agencies.
All wire rope will eventually deteriorate to a point where it is
no longer usable. Wire rope shall be taken out of service
when any of the following conditions exist.
WARNING
If the hydraulic system must be activated to extend or
retract the lift cylinder, ensure the rod end is properly
aligned with the lift cylinder attach fitting.
CAUTION
If removed, ensure the large access covers on each side
of the boom base section are installed before extending
the boom. Boom damage could occur.
CAUTION
When extending and retracting the boom during
alignment, movement should be stopped if a restriction is
encountered, and wear pads adjusted as necessary to
provide free travel of the affected boom tele section(s).
CAUTION
Wear gloves when handling wire rope. Moderate to minor
injury may result if using bare hands.
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