LINK ASSEM. 7K6320 - Caterpillar

Illustration 1 g03385240
(1) Hydraulic oil cooler
(2) Electrohydraulic control
(3) Implement Valve
(4) Lift Cylinder
(5) Tilt Cylinder
(6) Hydraulic Tank The 988K Wheel Loader is electrohydraulically controlled. The machine uses hydraulic power that is controlled by electronics to move the actuators. The electrohydraulic system is composed of the following systems: the main hydraulic system, the pilot system, the implement electronic control system, and the hydraulic fan system.The hydraulic tank is common to all of the systems. The pilot system consists of the following components: brake charging, implement steering pilot pump, pilot relief valve, solenoid valve (hydraulic lockout), pilot control actuators and accumulator charging valve. The pilot control actuators are attached to the main control valve. The actuators control the shifting of the stems. Also, the main control valve is equipped with a shuttle valve (ball resolver) and a pressure reducing valve (lowering control). The shuttle valve and the pressure reducing valve are used to supply pilot oil to the pilot control actuators for lowering the work tool with a dead engine.The 988K electro-hydraulic implement system is similar to the 988H. The optional ride control valve has been redesigned, the tilt regeneration valve has been eliminated, and the implement lockout and float solenoids are now mounted to the implement control valve. Oil flow from the steering system now supplements the implement system oil flow when necessary.The implement electronic control system consists of the following components: electrohydraulic control, electronic control module, switches, lift linkage position sensor and tilt linkage position sensor.The hydraulic fan system is standard on all 988K Wheel Loaders. The hydraulic fan system is an on-demand fan control system. As the need for more cooling arises, the fan system supplies more air flow through the radiator. The output of the hydraulic fan system is used to meet different cooling requirements during high ambient conditions or a light work application. For additional information about the hydraulic fan system, refer to the Systems Operation, "Hydraulic Fan System".If the machine is equipped with the optional ride control system, dual accumulators and a balancing valve will be connected to the lift cylinders. For additional information about the operation of the ride control system, refer to the Systems Operation, "Ride Control System".