BRACKET AS 9W0459 - Caterpillar

Illustration 1 g00357372
Schematic for the power train hydraulic system (1) Priority valve (2) Wire harness for the electronic control module (ECM) (3) Torque converter inlet relief valve (4) Transmission oil filter (5) Modulating valves and the main relief valve (transmission) (6) Steering and brake control valve (7) Steering clutches and brakes (8) Passage for the lubrication of the transmission and the bevel gear (9) Oil cooler (10) Torque converter outlet relief valve (11) Torque converter (12) Power train oil pump (13) Pump drive (14) Passage to the steering clutch and brake lubrication (15) Check valve (A) Transmission and controls section (B) Torque converter and lubrication section (C) Transmission and torque converter scavenge sectionThe power train hydraulic system uses pump (12). The pump consists of three sections.Power train oil pump (12) is mounted on the front of the bevel gear case. The pump is driven by an auxiliary drive shaft from the engine. The bevel gear case is used as the main sump for the power train oil system.Section (A) draws oil from the bevel gear case. The oil goes through a magnetic screen. Then, the oil flows to oil filter (4). Next, the oil flows to steering and brake control valve (6) and to modulating valves and main relief valve (5). A main relief valve controls the pressure in the circuit. The main relief valve is located in a manifold on top of the transmission planetary.The oil that flows past the main relief valve provides part of the lubrication and cooling for the transmission and bevel gear. Oil from section (A) is primarily used in order to control steering clutches and brakes (7) and the transmission clutches.Section (B) sends oil from the bevel gear case to priority valve (1). Priority valve (1) sends a portion of the oil to torque converter (11). The rest of the oil is used in order to lubricate the steering clutches, the brakes, and the transmission.The oil from torque converter (11) exits through outlet relief valve (10). Next, the oil flows to oil cooler (9). Then, the oil flows back to priority valve (1). At the priority valve, the oil combines with the oil that bypassed torque converter (11) .The combined oil flows from priority valve (1) in order to lubricate the transmission and steering clutches and brakes. A small portion of the oil is diverted from the torque converter inlet in order to lubricate the drive gears and bearings.Priority valve (1) normally sends oil from section (B) to torque converter (11), to steering clutches and brakes (7), and to the transmission for lubrication.When priority valve (1) is signalled by the electronic control module (ECM), the priority valve diverts oil from section (B) through check valve (15). The oil combines with the oil flow from section (A). Oil pressure increases until a minimum pressure is achieved for controlling steering clutches and brakes (7) and the transmission.Torque converter inlet relief valve (3) is located in priority valve (1). Torque converter inlet relief valve (3) limits