JLG M4069 ANSI Service Manual - Manual (Page 74)

SECTION 4 - HYDRAULICS
4-2 – JLG Lift – 3121122
2. Unless specific torque requirements are given within
the text, standard torque values should be used on
heat treated bolts, studs and steel nuts, in accor-
dance with recommended shop practices.
Hydraulic Lines and Electrical Wiring
Clearly mark or tag hydraulic lines and electrical wiring, as
well as their receptacles, when disconnecting or removing
them from the unit. This will assure that they are correctly
reinstalled.
Hydraulic System
1. Keep the system clean. If evidence of metal or rub-
ber particles are found in the hydraulic system, drain
and flush the entire system.
2. Disassemble and reassemble parts on clean work
surface. Clean all metal parts with non-flammable
cleaning solvent. Lubricate components, as
required, to aid assembly.
Lubrication
Service applicable components with the amount, type,
and grade of lubricant recommended in this manual, at
the specified interval. When recommended lubricants are
not available, consult your local supplier for an equivalent
that meets or exceeds the specifications listed.
Batteries
Clean batteries using a non-metallic brush and a solution
of baking soda and water. Rinse with clean water. After
cleaning, thoroughly dry batteries and coat terminals with
an anti-corrosion compound.
Lubrication and Servicing
Components and assemblies requiring lubrication and
servicing are shown in Section 1.
4.2 LUBRICATION INFORMATION
Hydraulic System
1. The primary enemy of a hydraulic system is contam-
ination. Contaminants enter the system by various
means, e.g.; inadequate hydraulic oil, allowing mois-
ture, grease, filings, sealing components, sand, etc.
to enter when performing maintenance, or by per-
mitting the pump to cavitate due to insufficient sys-
tem warm-up.
2. The design and manufacturing tolerances of the
component 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 generally results in faulty opera-
tion. 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 at the specified intervals
required in Section 1. Always examine filters for evi-
dence of metal particles.
3. Cloudy oils indicate a high moisture content which
permits organic growth, resulting in oxidation or cor-
rosion. 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 oper-
ating, are recommended for use.
NOTE: Metal particles may appear in the oil or filters of new
machines due to the wear-in of meshing compo-
nents.
Hydraulic Oil
1. Refer to Section 1 for recommendations for viscosity
ranges.
2. JLG recommends DTE 11Hydraulic Oil, which has
an SAE viscosity of 10W and a viscosity index of
140.
NOTE: Start-up of hydraulic system, not using DTE 11, with
oil temperatures below -15°F (-26°C) is not recom-
mended. If it is necessary to start the system in a
sub-zero environment, it will be necessary to heat
the oil with a low density, 100VAC heater to a mini-
mum temperature of -15°F (-26°C).
Changing Hydraulic Oil
1. Use of any of the recommended hydraulic oils elimi-
nates the need for changing the oil on a regular
basis. However, filter elements must be changed
after the first 50 hours of operation and every 250
hours thereafter. If it is necessary to change the oil,
use only those oils meeting or exceeding the specifi-
cations appearing in this manual. If unable to obtain
the same type of oil supplied with the machine, con-
sult local supplier for assistance in selecting the
proper equivalent. Avoid mixing petroleum and syn-
thetic base oils. JLG Industries recommends chang-
ing 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 contami-
nants from the service container. Always replace the
filter cartridge any time the system oil is changed.