approximately 1900 psi ( 134 kg/cm2) (13 1 10 kPa), the
oil opens poppet valve (21). The pressure of the pump oil
through the open poppet valve moves piston (22) and
plunger (24) until the plunger is not against detent balls
(25). Now, with plunger (24) away from the detent balls,
the balls come out of detents (26) as valve spool spring
(23) moves ejector valve spool (13) to HOLD position
Relief Valve for Cylinder Circuits
SCRAPER CONTROL VALVE
1. Oil line (from the pump). 2. Relief valve.
The relief valve (2) in the circuits for the bowl
cylinders, ejector cylinder and door cylinder is in the
control valve for the scraper. When the engine is
running, oil from the pump goes through line (1), with the
Tee test plug, and into the passage in the control valve
with relief valve (2).
The pressure setting of the relief valve can be
adjusted. The relief valve must be removed and
disassembled to change the amount of shims in the
Add shims for an increase or remove shims for a
decrease in the pressure setting of relief valve (2).
Relief Valve for Elevator Circuit
RELIEF VALVE FOR ELEVATOR
1. Housing. 2. Adjustment screw for relief valve. 3.
Pump oil line.
The housing (1), with the relief valve, is under the
machine and is near the left side of the frame. Housing
(1) is on the oil outlet of the drive end section of the
elevator hydraulic pump. When the engine is running, the
oil from the drive end section of the pump goes through
housing (I) and through line (3) to the elevator control
valve. The oil from the cover end section of the elevator
hydraulic pump is in the circuit with the relief valve when
the elevator speed lever is in both the HI and LOW
Turn adjustment screw (2) to change the pressure
setting for the relief valve. Turn the screw clockwise to
increase or counterclockwise to decrease the pressure
setting of the relief valve.