Keep The System Clean.
The following are known high stress areas applicable
to Grove machines, and visual inspection of these
When removing components of a hydraulic system,
areas should be made part of an owner's planned
cover all openings on both the component and the
preventive maintenance program:
a. Power Telescope Boom - wear pad
If evidence of foreign particles is found in the
retaining structures, hydraulic cylinder attaching
hydraulic system, flush the system.
points, boom pivot shaft retaining structures.
Disassemble and assemble hydraulic components on
b. Outrigger pads,
a clean surface.
Clean all metal parts in a nonflammable cleaning
c. Main frames - generally in the area of
fluid. Then lubricate all components to aid in
doubler plates and crossmembers; at the junction of
front and rear frame members on truck cranes.
d. Turntable bearing connection (where
bearing is welded to the crane superstructure or
Inspect all sealing elements (O-rings, gaskets, etc.)
when disassembling and assembling the hydraulic
system components. Installation of new elements is
e. Counterweight support structures.
f. Chassis axle and suspension mounting
When installing metal tubes, tighten all bolts finger-
g. Hydraulic cylinder end connections.
tight. Then, in order, tighten the bolts at the rigid end,
the adjustable end, and the mounting brackets. After
The above is provided only as a guide, your
tubes are mounted, install the hoses. Connect both
inspection plan should not be limited to the areas
ends of the hose with all bolts finger-tight. Position
listed. A thorough visual inspection of all weldments
the hose so it does not rub the machine or another
is good practice.
hose and has a minimum of bending and twisting.
Anyone requiring more detailed inspection
instructions and/or procedures many request same
Due to manufacturing methods there is a natural
by contacting: Manitowoc Crane CARE, PO Box 21,
curvature to a hydraulic hose. The hose should be
Shady Grove, PA. 17256-0021
installed so any bend is with this curvature.
FATIGUE OF WELDED STRUCTURES.
Experience has shown that highly stressed welded
structures when repeatedly subjected to varying
Loctite type adhesives contain chem-
stresses caused by twisting, shock bending and
icals that may be harmful if misused.
intentional and/or unintentional overloads, often
Read and follow the instructions on the
become subject to weld cracking which may be
attributed to fatigue of the welded joint.
condition is not uncommon in construction
Always follow the directions on the Loctite container
as not all Loctite types are suitable for all
Equipment should be periodically inspected for
evidence of weld fatigue. The frequency of these
Various types of Loctite are specified throughout the
inspections should be commensurate with the age of
the equipment, the severity of the application, and the
experience of the operators and maintenance