JLG 600SC_660SJC Service Manual - Manual (Page 110)

SECTION 5 - CAT CHASSIS (S/N 0300128000 TO PRESENT)
5-18 – JLG Lift – 3121157
Hydraulic Fluid Temperature during Operation
Temperature control of the hydraulic fluid is very important
in the hydraulic system. Higher temperature may degrade
the anti-oxidant resistivity and accelerate deterioration of
the hydraulic fluid. Therefore, take the following precau-
tions:
1. Maintain the temperature during continuous opera-
tion within the range from +10 to +80 degree.
2. Minimum start-up temperature should be at minus
+20 degree or higher. Maximum allowable tempera-
ture is +100 degree only for a short time (total accu-
mulative operating time under 100 degree should be
within 100h). These temperatures have been estab-
lished in consideration of degradation to viscosity
and anti-oxidant resistivity of the hydraulic fluid and
to the O-ring and oil seals. The motor life will be
shortened if the motor is continuously run at temper-
ature of +80 degree or higher.
Maintenance and Inspection
Perform maintenance and inspection of the motor for the
following check points unless a malfunction is detected:
1. Is there any oil leakage at flange connections and
joints of the equipment?
2. Is there any looseness in tightened bolts?
3. Is there any damage on the appearance?
4. Is there contamination in the lubricant?
5.6 PERIODIC INSPECTION AND CHANGE
CRITERIA
Hydraulic Fluid
Although the hydraulic oil is clean at first, it will be dirtied
with sediment such as sludge in the circuit and the tank
after a long operation, and it may cause damage to
hydraulic components. The hydraulic fluid will also be
degraded and will result in wear of the sliding compo-
nents. Therefore, it is necessary to check the hydraulic
fluid periodically and to change the fluid depending on the
state of degradation. However, it may be difficult to judge
quantitatively on site whether the fluid is degraded or not.
The following table is provided for information to be used
as a basis of visual inspection.
It is recommended to replace the oil with new after the first
500-hours of operation.
When hydraulic fluid is replaced, deposits such as deteri-
orated hydraulic fluid and sludge, and water are contained
in the circuit and tank. If left as they are, they will cause
operation failure of the motor and shorten its life-span. Be
sure to clean the tank and flush piping before replacing
with new hydraulic fluid.
Filters
Filtration effectivity is lowered if filter elements are
clogged. Periodic inspections are essential to maintain the
filters in good conditions.
Filters should be replaced with new ones after the first 50
hours of running, and checked after every 250 hours of
running. Where a differential pressure gauge is not pro-
vided, the filters should be replaced with new ones after
the first 50 hours and every 250 hours thereafter. The fil-
ters must be replaced with new ones when the hydraulic
fluid is replaced with new.
APPEARANCE * SMELL JUDGMENT
COUNTERM
EASURES
Transparent
(no discoloration)
Good Good Use as is
Transparent
(but dark spots are noted)
Good
Foreign sub-
stances mixed Use after
filtration
Discolored (milky) Good Water contained Change oil
Discolored (darkish) Bad Oxidized Change oil
* Visual Inspection Method
(Compare the old and new fluids in the test tubes)