8.3
3507, 3508, 3509, 3512, 3513, 4007, 4008, 4009, 4012, 4013
Hydraulic System
8.2
SAFETY INFORMATION
Petroleum-based hydraulic fluids are used in this
machine. The temperature of hydraulic fluid increases
during the operation of various hydraulic functions. A
heated petroleum-based hydraulic fluid presents a fire
hazard, especially when an ignition source is present.
Accordingly, periodically inspect all hydraulic system
components, hoses, tubes, lines, fittings, etc. Carefully
examine any deterioration and determine whether any
further use of the component would constitute a hazard.
If in doubt, replace the component.
Whenever you disconnect a hydraulic line, coupler, fitting
or other component, slowly and cautiously loosen the part
involved. A hissing sound or slow seepage of hydraulic
fluid may occur in most cases. After the hissing sound
has ceased, continue removing the part. Any escaping oil
should be directed into an appropriate container. Cap or
otherwise block off the part to prevent further fluid
seepage.
Hydraulic system maintenance will, at times, require that
the engine be operated. Always follow safety
precautions.
A major cause of hydraulic component failure is
contamination. Keeping the hydraulic fluid as clean as
possible will help avoid downtime and repairs. Sand, grit
and other contaminants can damage the finely machined
surfaces within hydraulic components. If operating in an
exceptionally dirty environment, change filters and
inspect the fluid more often. When servicing the system,
cap or plug hydraulic fittings, hoses and tube assemblies.
Plug all cylinder ports, valves and the hydraulic reservoir,
and pump openings until installation occurs. Protect
threads from contamination and damage.
Some hydraulic functions are actuated by interfacing with
electrical system components (switches, solenoids and
sensors). When the hydraulic system is not functioning
properly, check the electrical aspect of the malfunctioning
circuit also.
8.3
HYDRAULIC PRESSURE DIAGNOSIS
JLG Parts Department has a kit available to use for
hydraulic system maintenance and troubleshooting: the
JLG Pressure Test Kit. The kit is in a durable
polyethylene carrying case for demanding field service
conditions.
Pressure Test Kit
The hydraulic pressure test kit is used to pressure test the
various hydraulic components in the hydraulic system.
The kit includes:
• Gauges for testing high and low pressure circuits
• Fittings, couplers and hoses
• Durable carrying case
Contact your local
JLG
distributor for ordering
information.
WARNING:
DO NOT
service the
machine without following all safety
precautions as outlined in Section 1, “Safety
Practices,” of this manual. Failure to follow the
safety practices may result in death or serious
injury.
Part
Number
Description
Approximate
Weight
Price and
Availability
70000652 Hydraulic Pressure Test Kit
10 lbs.
Consult Factory
70000101 Digital Hydraulic Pressure
Test Kit
7 lbs.
Consult Factory
