FORK GP-GRAPPLE 1877287 - Caterpillar

Illustration 1 g00507916
Oil Filter Components
(1) Bypass valve
(2) Spring
(3) Switch
(4) Outlet passage
(5) Inlet passage
(6) Filter element
(7) Housing assembly The steering charge loop oil filter is located in the enclosure on the right side of the operator's compartment. The steering charge loop oil filter is the outside filter of the two filters.The pressure oil flows from the steering charge pump into the filter housing through inlet passage (5). The oil fills the space between the inside of housing assembly (7) and filter element (6). During normal operation, the oil flows through the filter element and out through outlet passage (4). The oil then flows to the bypass and pressure control group. Filter element (6) stops any debris that is in the oil.If the filter element is full of debris, the restriction to the flow causes a pressure increase on the outside of the filter. The pressure oil fills passage (5) and the oil causes bypass valve (1) to move against the force of spring (2). The oil then flows past the open bypass valve and to the remainder of the steering hydraulic system. When the oil does not go through the filter element, the debris in the oil causes damage to other components in the hydraulic system.The filter bypass valve opens when the pressure on the outside of the filter element is 175 kPa (25 psi) higher than the pressure on the inside of the filter element. Switch (3) is installed in inlet passage (5). Switch (3) is a normally open switch that is held closed by bypass valve (1). When the bypass valve opens to bypass the oil flow around the filter element, the switch opens. The EMS indicator and fault light come on and the fault alarm sounds. If this occurs and the oil is at the operating temperature, inspect the filter element for restrictions.Note: The warning function is disabled at oil temperatures below 38°C (100°F).Correct maintenance must be used to make sure that filter element (6) does not become full of debris. The debris will stop the flow of clean oil to the hydraulic system.