Hydraulic System & Component Maintenance And Repair; Maintenance Hints - Skyjack SJ 3215 Service Manual

Operator's Responsibility for Maintenance
Hydraulic System & Component
Maintenance and Repair
The following points should be kept in mind when
working on the hydraulic system or any component:
1. Any structure has limits of strength and durability.
To prevent failure of structural parts of hydraulic
components, relief valves which limit pressure to
safe operating values are included in the hydraulic
circuits.
2. Tolerance of working parts in the hydraulic system
is very close. Even small amounts of dirt or foreign
materials in the system can cause wear or damage
to components, as well as general faulty operation
of the hydraulic system. Every precaution must
be taken to assure absolute cleanliness of the
hydraulic oil.
3. Whenever there is a hydraulic system failure
which gives reason to believe that there are metal
particles or foreign materials in the system, drain
and flush the entire system and replace the filter
cartridges. A complete change of oil must be
made under these circumstances.
4. Whenever the hydraulic system is drained, check
the magnets in the hydraulic reservoir for metal
particles. If metal particles are present, flush the
entire system and add a new change of oil. The
presence of metal particles also may indicate the
possibility of imminent component failure. A very
small amount of fine particles is normal.
5. All containers and funnels used in handling
hydraulic oil must be absolutely clean. Use a
funnel when necessary for filling the hydraulic oil
reservoir, and fill the reservoir only through the
filter opening. The use of cloth to strain the oil
should be avoided to prevent lint from getting into
the system.
6. When removing any hydraulic component, be sure
to cap and tag all hydraulic lines involved. Also,
plug the ports of the removed components.
NOTE
Samples of hydraulic oil should be drawn
from the reservoir and tested annually.
These samples should be taken when the
oil is warmed through normal operation of
the system. The sample should be analyzed
by a qualified lubrication specialist to
determine if it is suitable for continued use.
SKYJACK, Page 14
Section 1 - Scheduled Maintenance
Oil change intervals will depend on the
care used in keeping the oil clean, and the
operating conditions. Dirt and/or moisture
cotamination will dictate that the oil should
be changed more often. Under normal use
and operating conditions, the hydraulic oil
should be changed every two years. Refer
to Table 1.2 of this manual.
7. All hydraulic components must be dis-assembled
in spotlessly clean surroundings. During
disassembly, pay particular attention to the
identification of parts to assure proper reassembly.
Clean all metal parts in a clean mineral oil solvent.
Be sure to thoroughly clean all internal passages.
After the parts have been dried thoroughly, lay
them on a clean, lint-free surface for inspection.
8. Replace all O-rings and seals when overhauling
any component. Lubricate all parts with clean
hydraulic oil before reassembly. Use small
amounts of petroleum jelly to hold O-rings in place
during assembly.
9. Be sure to replace any lost hydraulic oil when
completing the installation of the repaired
component, and bleed any air from the system
when required.
10. All hydraulic connections must be kept tight. A
loose connection in a pressure line will permit
the oil to leak out or air to be drawn into the
system. Air in the system can cause damage
to the components and noisy or erratic system
operation.

Maintenance Hints

Three simple maintenance procedures have the
greatest effect on the hydraulic system performance,
efficiency and life. Yet, the very simplicity of them may
be the reason they are so often overlooked. What are
they? Simply these:
1. Change filters annually. The filters will need
to be changed more often depending on
the operating conditions. Dirty, dusty, high
moisture environments may cause the
hydraulic system to be contaminated more
quickly.
2. Maintain a sufficient quantity of clean hydraulic
oil of the proper type and viscosity in the
hydraulic reservoir.
3. Keep all connections tight.
SJIII Series