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HYDRAULIC SAFETY
Be careful of:
1. Leaks
a. Puddles of fluid are slippery and hazardous.
b. Most hydraulic oils will vaporize and ignite,
disastrous fires are possible.
c. Leaking fluid may be hot and can produce
severe burns.
d. Fluid can squirt out under high pressure
with dangerous force. Pin hole jets can
pierce skin and damage eyes.
CAUTION: Escaping fluid under pressure
can penetrate the skin, causing serious
personal injury. Relieve pressure before
disconnecting hydraulic or other lines.
Tighten all connections before applying
pressure. Use a piece of cardboard or
paper to search for leaks.
Never use your hand!
If any fluid is injected into the skin, it must
be surgically removed within a few hours
by a doctor familiar with this type injury or
gangrene may result.
2. Hot Components
a. Pumps and motors
b. Relief valves
c. Anyplace fluid has been flowing fast under
pressure.
CAUTION: Always wear safety goggles or
safety glasses during maintenance.
3. Stored energy
a. Even with the power unit off, there may be
energy stored in the system due to:
b. Stalled feedwheels
c. Suspended loads - booms - stabilizers
d. Charge accumulators
e. Electrical voltage
IMPORTANT: Never boost pressure settings on
hydraulics, this will void the manufacturer's war-
ranty.
A hydraulic pump makes oil flow but there must be
resistance for the flow to generate pressure.
UNDERSTANDING HYDRAULICS
If a motor or a cylinder does not work or works slowly,
the fluid must be slipping through it or bypassing the
work completely. Trace the lines to the motor or the
cylinder, then place a pressure check on the working
line.
When the pump is working at the proper Gallons Per
Minute (GPM) and the pressure checks out OK, you
will find that in most cases your motor or your cylinder
is defective.
If the pressure is too low, the pump or the relief valve
is causing the difficulties Clean relief valve thor-
oughly (See Inspecting Relief Valves). Reassemble
relief valve and check the pressure again.
Example:
If the pump is pumping six gallons in 30 seconds and
the pump is a 12 GPM, then you know that it is
performing at capacity. If it will only pump two or
three GPM in 30 seconds, you know that the pump is
only performing at 50% of its capacity.
If the pump is performing properly, the relief valve is
defective.
If the pump isn't performing right, it will need repairing
or replacement.
When the pump is pumping at the proper GPM and the
pressure is correct, you will find in most cases your
hydraulic motor or cylinder is defective.
FILTERS
The filters mounted on the hydraulic tank are 10
absolute micron and should not be replaced with any
filter not meeting or exceeding this rating.
HYDRAULIC OIL
Change hydraulic oil every 2000 operating hours or
one year under normal conditions and every 1000
hours, 6 months, whichever comes first, under ex-
tremely dirty conditions. If hydraulic component
failure is a regular maintenance problem, monthly
testing of the system will help determine your change
periods.
IMPORTANT: Do not use any hydraulic oil that
does not contain anti-wear additives.
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