ROD AS 3174922 - Caterpillar

Illustration 1 g00850809
Oil Filter Construction
(1) Cover
(2) Bolt
(3) Plug
(4) Plug
(5) Oil inlet passage
(6) Oil outlet passage
(7) Filter housing
(8) Filter elements
(9) Plug
(10) Passage
(11) Bypass valve
(12) Bypass valve spring
(13) Passage
(14) Seal
(15) Nut
(16) Plug
(17) Retainer Pressure oil from the oil pump flows into filter housing (7) through inlet passage (5). The oil fills the space between filter elements (8) and the inside of housing (7). During normal operation, the oil flows through filter elements (8) to passage (13). The oil then flows through outlet passage (6) to the remainder of the hydraulic system. The filter elements stop any debris that is in the oil.If the filter elements become full of debris, then the restriction to the oil flow will cause an increase in pressure inside the filter. The pressure oil fills passage (10). This causes bypass valve (11) to move against the force of spring (12). The oil then flows past the open bypass valve and through outlet passage (6) to the remainder of the hydraulic system. When the oil does not flow through the filter elements, the debris in the oil will cause damage to other components in the hydraulic system.
Illustration 2 g01200826
Oil Filter Location
(18) Oil filter.
Correct maintenance must be used to ensure that filter elements (8) do not become full of debris. This would stop the flow of clean oil to the hydraulic system.During normal operation, the end of bypass valve (11) is in contact with a switch plunger. This keeps the filter bypass switch for the transmission in the OFF position.Bypass valve (11) moves away from the switch plunger when the bypass valve opens. The switch plunger moves away from the switch contacts. The switch plunger then opens the circuit. This indicates that the filter elements are plugged and that the bypass valve is open. At this time, a Warning Category 3 will appear on the Caterpillar Monitoring System.The warnings occur only when the oil in the system is at normal operating temperature.