Lull 6K Service Manual - Manual (Page 148)

Supply, Pressure, and Return Hydraulics
5-4 Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
The term “mid-inlet hydraulic system” is used to reference and differentiate
the types of components used in the hydraulic system. This system was
designed to simplify the hydraulic system and improve overall reliability. It
uses a rear axle stabilizer control valve along with a mid-inlet directional
control valve assembly to control all hydraulic functions.
General Hydraulic Maintenance Practices
Safe Maintenance Practices
• The hydraulic system is under pressure whenever the engine is run-
ning and can hold pressure after the engine is shut down. After forks or
attachments are resting on the ground or support, make sure pressure
is relieved from all hydraulic lines and components before removing
them from the circuit.
Remember the following during inspection and maintenance of the
hydraulic system:
• Wait for fluid to cool down before disconnecting lines.
• DO NOT use your hand to check for leaks. Use a piece of cardboard or
paper to search for leaks.
• Wear appropriate eye protection.
• If anyone is injured by or if any hydraulic fluid is injected into the skin,
get medical attention immediately.
• When venting or filling the hydraulic system, loosen the filler cap slowly
and remove it gradually.
• NEVER reset any relief valve in the hydraulic system to a pressure
higher than that shown in the Specifications Section of this manual.
Cleanliness
Cleanliness is critical when servicing hydraulic systems.
WARNING
HIGH PRESSURE FLUID
HAZARD
To prevent serious personal
injury or death:
• Relieve system pressure
before adjusting,
repairing, or
disconnecting
components.
• Wear proper hand and
eye protection. Use
cardboard to search for
leaks.
• Keep all components in
good repair.
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