GUARD AS 1197015 - Caterpillar

Illustration 1 g03385154
(1) Line to the oil cooler inlet
(2) Makeup line
(3) Line from the oil cooler outlet
(4) Check valve housing
(5) Return line to the hydraulic tank
Illustration 2 g03385422
(1) Line to the oil cooler inlet
(3) Line from the oil cooler outlet
(4) Check valve housing
(5) Return line to the hydraulic tank
(6) Bypass check valve
(7) Return passages
(8) Slow return check valve Slow return check valve (8) is contained in check valve housing (4). Slow return check valve (8) is located between the main control valve and the hydraulic tank in the return circuit. The slow return check valve restricts the return oil flow. This restriction causes a pressure increase in the return hydraulic system and makeup line (2).If cavitation occurs in the swing motor, oil from return passage (7) in the main control valve flows into makeup line (2). This makeup oil is supplied to the inlet port of the swing motor in order to prevent cavitation in the swing motor.Note: For more information on the makeup operation, refer to System Operation, "Oil Makeup (Swing System)".The return oil that flows through the check valve housing (4) is divided into two flow paths. A portion of the oil flows through slow return check valve (8) and inlet line (1) to the hydraulic oil cooler. Cooled oil from the hydraulic oil cooler flows through outlet line (3) and return line (5) to the return filter in the hydraulic tank. The remainder of the oil flow from the check valve housing (4) flows through the bypass check valve (6), through return line (5) to the return filter in the hydraulic tank. The bypass check valve (6) is contained in check valve housing (4).