Pump Synchronization - Test and Adjust
SMCS Code: 3203-025-SY; 3203-081-SY
Personal injury or death can result from sudden machine
Sudden movement of the machine can cause injury to
persons on or near the machine.
To prevent injury or death, make sure that the area around
the machine is clear of personnel and obstructions before
operating the machine.
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
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
(1) Test port for axle propel pump in REVERSE. (2) Test port
for drum propel pump in REVERSE. (3) Test port for drum
propel pump in FORWARD. (4) Balance lines. (5) Test pot for
axle propel pump in FORWARD.
Connect four 60000 kPa (8700 psi) pressure gauges to
pressure test ports (1), (2), (3), and (5). Mark the
gauges in order to correspond with the pressure test
ports. Use lines that are long enough in order to allow
the operator to read the gauges from the driver's seat.
Disconnect one end of each balance line (4). Plug the
balance lines and cap the fittings for the balance lines.
Start and run the engine at high idle until the hydraulic
oil reaches 38C (100F). Engine rpm should be 2350 ±
Move the speed selection switch to the LOW SPEED
Release the parking brake.
Move the propel control lever forward. Position the
propel control lever halfway between NEUTRAL and
FULL SPEED. Record the reading of the pressure
gauges that are connected to pressure test ports (3) and
Move the propel control lever in the reverse direction.
Position the propel control lever halfway between
NEUTRAL and FULL SPEED. Record the reading of
the pressure gauges that are connected to pressure test
ports (1) and (2).
It may be necessary to record all four of the
pressures in one direction if the results seem
irregular. This may help to determine the cause of
a problem within the propel system.
Move the speed selection switch to the HIGH SPEED