DISC 5374574 - Caterpillar

Illustration 1 g01229260
Schematic for the power train hydraulic system (1) Transmission Lubrication Pressure (L1) (2) Accumulator (3) Main Relief Pressure (P) (4) Main Relief Valve (5) Passage for the lubrication of the transmission and the bevel gear (6) Steering Differential and Brake (7) Lubrication Pressure for the Left Brake (LB1) (8) Brake Pressure for the Left Brake (9) Brake Pressure (B1) (10) Electronic Brake Control Valve (11) Lubrication Distribution Manifold (12) Torque Converter Inlet Relief Valve (13) Torque Converter Inlet Pressure (M) (14) Torque Converter Outlet Pressure (N) (15) Torque Converter Outlet Relief Valve (16) Screen (18) Lubrication Pressure for the Flywheel (L2) (19) 3176C Engine (20) Power Train Oil cooler (21) Torque Converter (22) Vent line (23) Magnetic Screen (24) Torque converter and lubrication section (A) (25) Transmission and controls section (B) (26) Transmission and torque converter scavenge section (C) (27) Scheduled Oil Sampling (S.O.S.) (28) Transmission Oil Filter and Bypass Valve (29) Passages for lubrication of the steering differential (30) Lubrication Pressure for the Right Brake (LB2) (31) Brake Pressure for the Right Brake (32) Planetary Gears and Brake (33) Screen (34) Transmission and Transmission Modulating ValvesThe power train hydraulic system uses a three-section pump. The oil pump is mounted on the gear case for the bevel and transfer gears. The pump is driven by an auxiliary drive shaft from the engine.Torque Converter and Lubrication Section
Section (A) sends oil from the bevel gear case. The oil goes through a magnetic screen (23). Next, the oil flows to torque converter inlet relief valve (12). Torque converter inlet relief valve (12) is located in lubrication distribution manifold (11). Torque converter inlet relief valve (12) limits the maximum oil pressure to torque converter (21). The inlet relief valve sends most of the oil to torque converter (21). The rest of the oil is sent to the lubrication distribution manifold. The oil is used to lubricate the brakes and the transmission.The oil from torque converter (21) exits through outlet relief valve (15). Next, the oil is routed to oil cooler (20). Then, the oil flows back to lubrication distribution manifold (11). At the lubrication distribution manifold, the oil combines with the oil that bypassed torque converter (21) .The combined oil flows from lubrication distribution manifold (11) in order to lubricate the transmission and brakes. Then, the oil drains to the bevel gear case. A small portion of the oil is diverted from the torque converter inlet in order to lubricate the drive gears and bearings.Transmission and Controls Section
Section (B) of the pump draws oil from the bevel gear case. The oil goes through a magnetic screen (23). Then, oil flows to oil filter (28). Next, the oil flows to brake control valve (10), the modulating valves (34), the accumulator (2), and main relief valve (4). The main relief valve is located in the manifold on the top of the transmission. The main relief valve controls the pressure in the circuit.The oil that flows past the main relief valve provides part