When the vibratory system or propel system are not in use the
charge pressure of charge relief valve (7) is measured at the
vibratory flushing valve. Refer to the Testing and Adjusting
section for the pressure values. The case drain oil from the
vibratory pump and motor cases goes to hydraulic oil tank (13).
Excess charge oil that passes through the propel pumps goes
to vibratory flushing valve (10) and the oil cooler before
returning to the hydraulic oil tank.
Charge oil enters into closed circuit loop lines (4) and (11)
through check valves (5) and (12). Because the charge
pressure in both closed circuit loop lines is equal, the shuttle
valve spool inside vibratory flushing valve (10) is held in center
position and oil flow from both sides of loop flow to oil cooler.
When the propel system is in operation, hot low pressure oil
flows from the propel cooling valve to the oil cooler. When
measured at the vibratory flushing valve, relief valve (2) limits
the charge pressure for the vibratory system and propel
system to 1725 345 kPa (250 20 psi) at 38C (100F)