Charge Relief Valve.
(11) Adjustment screw. (12) Spring. (13) Port to oil cooler. (14) Port
to propel and vibratory flushing valve. (15) Piston.
The charge relief valve maintains charge oil pressure while the
machine is in operation. Low pressure loop oil from the propel
cooling valve and vibratory flushing valve put pressure on port
(14). When the pressure on the end of piston (15) is greater
than the force of spring (12), piston (15) moves and allows oil
to go through port (13) to the oil cooler. Screw (11) is used to
adjust the valve pressure setting.