Lull 944E-42, Service Manual

Page: 258 / 844

Hydraulic System
8.8 Model 644E-42/944E-42 Rev. 6/04
8.5 HOSES, TUBE LINES, FITTINGS, ETC.
There are numerous hydraulic hoses, tubes, fittings, etc.
used on this vehicle. Periodically inspect all of these and
carefully examine any signs of wear, abrasion and/or
deterioration. Determine whether any further use of the
component would constitute a hazard. If in doubt, replace
the component.
8.5.1 Replacement Considerations
Conditions including, but not limited to, the following are
sufficient for considering component replacement:
1. Any evidence of hydraulic fluid leakage at the
surface of a flexible hose or its junction with the
metal and couplings
2. Any blistering or abnormal deformation to the outer
covering of a hydraulic hose
3. Hydraulic oil leakage at any threaded or clamped
joint that cannot be eliminated by normal tightening
or other recommended procedures.
4. Evidence of excessive abrasion or scrubbing on the
outer surface of a hose, rigid tube, or hydraulic
fitting. Modification must be made to eliminate the
interference of the elements in contact with one
another, or to otherwise protect the components
from contact with one another. Slightly moving a
hose or adjusting a plastic tie wrap may often be all
that is necessary to eliminate interference; evaluate
each situation and proceed as required by the
individual circumstances.
8.5.2 Hose, Tube, Line and Fitting
Replacement
Before removing a hydraulic hose or component, always
mark or otherwise label the related parts and the exact
location of the hose or component to aid in proper
re-installation. Hydraulic fluid is a good cleaner and can
remove most liquid-ink type markings, so make sure the
mark or label will remain intact. Alternative methods to
using markers include color-coded tie wraps, number-tag
sets, alpha-numeric stampings or markings and suitably
labeled pieces of tape. Select an appropriate marking
method for the conditions and proceed accordingly.
NEVER replace a hydraulic hose or other component
with a part not specifically designed for this vehicle. For
example, replacing a hydraulic hose rated for use in a
3700 psi (255 bar) circuit with a common garden hose
can result in an exploded garden hose, hydraulic fluid
spray and other damage or personal injury. Use only
factory approved parts for best performance and safety.
Removal and replacement of hoses, tube lines, fittings,
etc. usually involves straight forward procedures. When
removing a hydraulic hose or other component, be aware
that o-rings are used throughout the hydraulic system.
ALWAYS replace a used o-ring with a new part.
Check all routing of hoses, wiring and tubing for sharp
bends, or interference with any rotating members. Install
appropriate protective devices such as tie wraps and
conduit to help shield hoses from damage. All tube and
hose clamps must be tight.
8.5.3 Snap Lock Fittings & Special Tools
The fittings on the block located on the transfer carriage
are a special snap lock fitting (1). These fittings require
the use of special tools (2) to release the locking
mechanism (3).
These snap lock connectors are manufactured by Eaton
Fluid Power. These fittings must be replaced with fittings
from Eaton Fluid Power. Other fittings, of similar design,
might look the same, but will not lock in place.
When servicing the snap lock connectors, they will also
require specially made plugs and caps. These parts may
be obtained through the JLG Parts Department.
Part Number Description
8024045 Service Kit, STC Hose Connections (*Included)
7301438 *Service Tool, STC Hoses 8-12
7301666 *Plug, -12 STC, MALE
7301667 *Cap, -12 STC, FEMALE
7301663 *Cap, -8 STC, FEMALE
7301662 *Plug, -8 STC, MALE
MU0380
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