HYDRAULIC AR 2582426 - Caterpillar

Illustration 1 g00466215
Location of the priority valve (1) Priority valve.The priority valve (1) is located on the right side of the machine.
Illustration 2 g00466312
Location of the priority valve and lines (1) Priority valve. (2) Outlet port to implement system. (3) Load sensing port. (4) Tank port. (5) Outlet port to the metering pump. (6) Supply port from the gear pump.The priority valve (1) is mounted to the lower right side of the frame. There are five lines that are connected to the priority valve. Oil flows from the gear pump into the supply port (6) . Oil flows to the metering pump through outlet port (5) . Oil flows to the implement system through outlet port (2) . Signal pressure from the metering pump flows through the load sensing port (3) . Oil is returned to the tank through tank port (4) .
Illustration 3 g00470018
Cross sectional view with no system pressure. (1) Priority valve. (2) Outlet port to implement system. (3) Load sensing port. (4) Tank port. (5) Outlet port to the metering pump. (6) Supply port from the gear pump. (7) Chamber. (8) Spring. (9) Load sensing orifice. (10) Signal pressure limiting valve. (11) Spool. (12) Dynamic bleed orifice. (13 ) Orifice for dampening. (AA) Supply Oil. (BB) Oil to the metering pump. (CC) Signal oil from the metering pump. (DD) Oil to the tank.With no pressure in the system, the spring (8) holds the spool (11) to the position shown in illustration 3. This restricts the outlet port to the implement system (2) . This also opens the outlet port to the metering pump (5) . When the engine is started, the system pressure increases. Oil flows from the supply port (6) to the outlet port to the metering pump (5) .
Illustration 4 g00466347
Cross sectional view. The steering wheel is not being turned. (1) Priority valve. (2) Outlet port to implement system. (3) Load sensing port. (4) Tank port. (5) Outlet port to the metering pump. (6) Supply port from the gear pump. (7) Chamber. (8) Spring. (9) Load sensing orifice. (10) Signal pressure limiting valve. (11) Spool. (12) Dynamic bleed orifice. (13 ) Orifice for dampening. (AA) Supply Oil. (BB) Oil to the metering pump. (CC) Signal oil to the metering pump. (DD) Oil to the tank.When the steering wheel is not turned, the pressure increases in the outlet port to the metering pump (5) . Pressure is felt through orifice (13) and the bottom of the spool (11) . The spool shifts up to the top. The supply oil (AA) from port (6) flows to the outlet port (2) and to the implement system.Oil also flows to the chamber (7) through the dynamic bleed orifice (12) .