JLG 600SC_660SJC Service Manual - Manual (Page 37)

SECTION 2 - GENERAL
3121157 – JLG Lift – 2-5
Changing Hydraulic Oil
1. Use of any of the recommended crankcase or
hydraulic oils eliminates 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 300 hours thereafter. If it is necessary to
change the oil, use only those oils meeting or
exceeding the specifications appearing in this man-
ual. If unable to obtain the same type of oil supplied
with the machine, consult local supplier for assis-
tance in selecting the proper equivalent. Avoid mix-
ing 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 contami-
nants 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 main-
tenance 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 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, upper boom fully
extended with the rated load in the platform and power off.
Maximum allowable drift is 2 inches (5 cm) in 10 minutes.
If the machine does not pass this test, proceed with the
following.
Cylinder Drift
Drift is to be measured at the cylinder rod with a calibrated
dial indicator. The cylinder oil must be at ambient temper-
ature and temperature stabilized.
The cylinder must have the normal load, which is the nor-
mal platform load applied.
If the cylinder passes this test, it is acceptable.
NOTE: This information is based on 6 drops per minute cyl-
inder leakage.
Table 2-2. Cylinder Drift
Cylinder Bore Diameter
Max. Acceptable Drift
in 10 Minutes
inches mm inches mm
3 76.2 0.026 0.66
3.5 89 0.019 0.48
4 101.6 0.015 0.38
5 127 0.009 0.22
6 152.4 0.006 0.15
7 177.8 0.005 0.13
8 203.2 0.0038 0.10
9 228.6 0.0030 0.08