RADIATOR GP 5088112 - Caterpillar

Illustration 1 g00904260
The inlet manifold is part of the main control valve (implement).Reference: See Systems Operation/Testing and Adjusting, "Location of Hydraulic Components" for the location of the inlet manifold on the implement control valve.The inlet manifold includes the following components:
Valve Assembly (Steering priority)
Screens (75 and 100 micron)
Relief Valve (load sensing oil)
Flow Control Valve (Dump valve for the load sensing oil)
Check valvesSteering Priority Valve
The flow of oil from the hydraulic piston pump is prioritized by the steering priority valve. The priority valve satisfies the demands from the steering system before the demands from the implement system.Screens (75 and 100 Micron)
The inlet section of the main control valve (implement) contains three screens. The screens are dedicated to the following circuits:
The system for the pilot supply (75 micron)
Load sensing oil system for the priority valve (100 micron)
Drain for the load sensing oil for the implement system (100 micron)Flow Control Valve (Dump valve for the load sensing oil)
The Flow Control Valve is installed in order to provide a drain back to the hydraulic tank for the load sensing signal once the load has been reduced on the machine requirements. The signal drain valve is pressure compensated.Relief Valve (Load sensing oil)
The Relief valve (Load sensing oil) is the main implement pressure relief valve for the hydraulic system. The signal limiter valve limits the maximum pressure in the load signal system. The relief valve has a pressure setting of 22800 kPa (3300 psi).Check Valve
When the spool in the steering priority valve moves up, pressure from the top side of the spool is exhausted through the check valve.Steering Not Activated
Illustration 2 g01023649
This schematic shows the steering priority valve in operation. (1) Check valve (2) Line to implement system (3) Valve As (Steering priority) (4) Return oil from implement system (5) Spring (6) Orifice (7) Line to metering pump (8) Screen (9) Orifice (10) Line to metering pump (11) Pump supply (12) Load sensing oil from implements (13) Load sensing oil from implement system (14) Relief valve (Load sensing oil) (15) Line to implement system (16) Tank (17) Check valve (Return oil back pressure) (18) Flow Control Valve GP (Dump valve for the load sensing oil)When the steering wheel is stationary, there is no demand from the metering pump for oil. The spool in the steering metering unit is spring centered and the oil is blocked at the spool. This causes an increase in pressure in supply line (10) to the metering pump. The increased pressure acts upon the top of the priority valve spool. The spool proportionally moves down against the force of spring (5). The mid-position of the spool allows oil flow to the steering system and to the implement control system. Further movement of the spool in the steering priority valve closes off the majority of the supply of oil to the steering system. Most of the oil flow through the priority valve is then supplied to the implement system through line (15) .Orifice (6) and orifice (9) allow a small