Testing and Adjusting
Hydraulic Oil Contamination - Test
SMCS Code: 4300-008; 5050-008
Escaping fluid under pressure, even a pinhole size leak,
can penetrate body tissue, causing serious injury, and
possible death. If fluid is injected into your skin, it must
be treated immediately by a doctor familiar with this type
Always use a board or cardboard when checking for a
Personal injury can result from hydraulic oil pressure and
Hydraulic oil pressure can remain in the hydraulic system
after the engine has been stopped. Serious injury can be
caused if this pressure is not released before any service
is done on the hydraulic system.
Make sure all of the attachments have been lowered, oil is
cool before removing any components or lines. Remove
the oil filler cap only when the engine is stopped, and the
filler cap is cool enough to touch with your bare hand.
Care must be taken to ensure that fluids are contained
during performance of inspection, maintenance, testing,
adjusting and repair of the product. Be prepared to collect
the fluid with suitable containers before opening any
compartment or disassembling any component containing
Refer to Special Publication, NENG2500, "Caterpillar Tools
and Shop Products Guide" for tools and supplies suitable
to collect and contain fluids on Caterpillar products.
Dispose of all fluids according to local regulations and
If the oil becomes contaminated, premature component failure
could result. Contaminated oil can also contribute to
Use the following procedure in order to determine the
contamination of the oil in the hydraulic system.
Check the hydraulic filter element for foreign materials.
Bronze colored particles give an indication of pump or
motor port plate failure.
Shiny steel particles give an indication of pump or
motor piston failure.
Rubber particles indicate a seal failure or a hose
Aluminum particles give an indication of gear pump
NOTE: If any of these particles are found in the hydraulic
filter element, all components of the hydraulic oil
system must be cleaned. Do not use any
damaged parts. Any damaged parts must be
removed and new parts must be installed.
Gear Pump Flow - Test
SMCS Code: 4306-032-ON; 4306-032-TB; 5073-032-ON;
Sudden movement of the machine or release of oil under
pressure can cause injury to persons on or near the
To prevent possible injury, perform the procedure that
follows before testing and adjusting the leveling blade