JLG 19AMI (3120875) Service Manual - Manual (Page 24)

SECTION 2 - SERVICE PROCEDURES
2-8 – JLG Lift – 3120875
2.5 LUBRICATION INFORMATION
Hydraulic System
The primary enemy of a hydraulic system is contamina-
tion. Contaminants enter the system by various means,
e.g., using inadequate hydraulic oil, allowing moisture,
grease, filings, sealing components, sand, etc., to enter
when performing maintenance, or by permitting the pump
to cavitate due to insufficient system warm-up or leaks in
the pump supply.
The design and manufacturing tolerances of the compo-
nent working parts are very close, therefore, even the
smallest amount of dirt or foreign matter entering a system
can cause wear or damage to the components and gener-
ally results in faulty operation. Every precaution must be
taken to keep hydraulic oil clean, including reserve oil in
storage.
Cloudy oils indicate a high moisture content which per-
mits organic growth, resulting in oxidation or corrosion. If
this condition occurs, the system must be drained,
flushed, and refilled with clean oil.
It is not advisable to mix oils of different brands or types,
as they may not contain the same required additives or be
of comparable viscosities. Good grade mineral oils, with
viscosities suited to the ambient temperatures in which
the machine is operating, are recommended for use.
NOTE: Metal particles may appear in the oil of new
machines due to the wear-in of meshing compo-
nents.
Hydraulic Oil
For best performance, JLG recommends the use of ISO-
Vg grade 32, 46 oil with a viscosity range between 32-54
cST at 40 degrees C (15-250 SUS at 100 degrees F).
Refer to Section 7 for recommended hydraulic oils.
Changing Hydraulic Oil
Use of any of the recommended hydraulic oils eliminates
the need for changing the oil on a regular basis. If it is nec-
essary to change the oil, use only those oils meeting or
exceeding the specifications appearing in this manual. If
unable to obtain the same type of oil supplied with the
machine, consult local supplier for assistance in selecting
the proper equivalent. Avoid mixing petroleum and syn-
thetic base oils. JLG Industries recommends changing the
hydraulic oil annually.
Use every precaution to keep the hydraulic oil clean. If the
oil must be poured from the original container into
another, be sure to clean all possible contaminants from
the service container.
While the unit is shut down, a good preventive mainte-
nance measure is to make a thorough inspection of all
hydraulic components, lines, fittings, etc., as well as a
functional check of each system, before placing the
machine back in service.
Lubrication Specifications
Specified lubricants, as recommended by the component
manufacturers, are always the best choice, however,
multi-purpose greases usually have the qualities which
meet a variety of single purpose grease requirements.
Should any question arise regarding the use of greases in
maintenance stock, consult your local supplier for evalua-
tion. Refer to Table 1-2. for an explanation of the lubricant
key designations appearing in the Lubrication Chart.