TUBE AS 3114001 - Caterpillar

Illustration 1 g00657085
Steering oil filter (1) Bypass valveThe steering charge loop oil filter is located in the enclosure on the left side of the operator's compartment.The pressure oil flows from the steering pump into the filter housing through the inlet passage. The oil fills the space inside the filter element. During normal operation, the oil flows through the filter element and through the outlet passage. The oil then flows to the pressure control valve. The filter element 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 opens bypass valve (1). 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 172 kPa (25 psi) higher than the pressure on the inside of the filter element. A switch is installed in the filter base. The switch 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 the filter element does not become full of debris. The debris will stop the flow of clean oil to the hydraulic system.