Flushing Valve Charge Relief Valve Pressure Test
The procedure described in this test will measure
charge pressure when the propel control lever is
in the NEUTRAL position and the vibratory
system is off. This charge pressure is measured
and recorded at the cooling manifold.
(1) Charge pressure test port. (2) Charge relief valve. (3) Adjustment
screw. (4) Locknut.
Connect a 0 to 4000 kPa (580 psi) pressure gauge to
charge pressure test port (1) on the flushing manifold.
Engage the parking brake. Put the propel control lever
in the NEUTRAL position. Start and run the engine at
high idle until the hydraulic oil temperature reaches
38C (100F). Engine rpm should be 2350 50 rpm.
With the propel system in neutral and the vibratory
system OFF, record the pressure on the gauge
connected to the test port. The charge relief valve
setting should be 1725 138 kPa (250 10 psi).
Charge pressure is determined by the steering pump
output, the internal leakage of the closed loop circuit,
the charge relief valves in each pump (one vibratory and
two propel) and open centered shuttle and charge relief
valves in the flushing manifold. If the charge pressure is
not correct, check the shim thickness of the charge relief
valve in the pump. The thickness should be 11.4 mm
(.45 in). Check that the orifice is not plugged. The
charge relief valve normally should not be adjusted. If
the shim thickness is correct, adjust the charge relief
valve in the flushing manifold. Loosen locknut (4) and
turn adjustment screw (3). After proper adjustment is
made tighten the locknut.
Once the charge relief valve pressure is correct, remove
Vibratory Frequency Test (Variable Frequency)
Drum Vibration Tachometer
Side View of Operator Console.
(1) Vibrations per minute control dial.