JLG 340AJ Service Manual - Manual (Page 34)

SECTION 2 - GENERAL
2-4 – JLG Lift – 3121259
2. 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 sys-
tem can cause wear or damage to the components and
generally results in faulty operation. Every precaution
must be taken to keep hydraulic oil clean, including
reserve oil in storage. Hydraulic system filters should be
checked, cleaned, and/or replaced as necessary, at the
specified intervals required in the Lubrication Chart in
Section 1. Always examine filters for evidence of metal
particles.
3. 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.
4. 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 or filters of new
machines due to the wear-in of meshing components.
Hydraulic Oil
1. Refer to Section 1 for recommendations for viscosity
ranges.
Changing Hydraulic Oil
1. Filter elements must be changed after the first 50 hours
of operation and every 300 hours (unless specified oth-
erwise) thereafter. If it is necessary 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 sup-
plier for assistance in selecting the proper equivalent.
Avoid mixing petroleum and synthetic base oils. JLG
Industries recommends changing the hydraulic oil
annually.
2. 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. Always clean the mesh element of
the filter and replace the cartridge any time the system
oil is changed.
3. 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-pur-
pose 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, con-
sult your local supplier for evaluation. Refer to Section 1 for an
explanation of the lubricant key designations appearing in the
Lubrication Chart.
2.4 CYLINDER DRIFT TEST
Maximum acceptable cylinder drift is to be measured using
the following methods.
Platform Drift
Measure the drift of the platform to the ground. Lower booms
(if equipped) slightly elevated, main boom fully extended with
the rated load in the platform and power off. Maximum allow-
able drift is 2 inches (5 cm) in 10 minutes. If the machine does
not pass this test, proceed with the following.