PLATE-RH 4J5567 - Caterpillar

Illustration 1 g00807419
(1) Spring (2) Orifice (3) Spool (4) Pump port (5) Orifice (6) Port (pilot pressure) (7) Orifice (8) Port (metering pump) (9) Load sensing port
Illustration 2 g00807483
The signal and pressure reducing valve is located on the right side of the machine.The signal and pressure reducing valve meters oil flow from the piston pump (steering) to the metering pump. The signal and pressure reducing valve increases the response time of the steering. Pump port (4) is connected to the piston pump and port (8) is connected to the metering pump.When the steering wheel is stationary, spool (3) is moved to the left and oil flows through orifice (2) and into the load sensing line from load sensing port (9). Oil also flows though orifice (5) and orifice (7) to the metering pump from port (6) .When the steering wheel is rotating, increased load sensing pressure is transmitted from the metering pump to load sensing port (9). Load sensing pressure and spring (1) move the spool to the right. This allows increased oil flow from port (8) to the metering pump. The flow rate from port (6) to the metering pump is also increased. This results in the rapid transmission of pressure to the metering pump.