ENGINE OIL COOLER 4N3719 - Caterpillar

When the engine is started, the transmission oil pump (11) pulls oil from oil sump (14). The oil flows through the suction screen and magnet (13). Transmission oil pump (11) sends pressurized oil through transmission oil filter (4). Pressurized transmission oil flows from the transmission oil filter to the oil inlet in the torque converter housing. The pressurized oil flows through internal passages in the torque converter housing in order to supply transmission hydraulic control relief valve (1) with oil. The pressurized oil also flows through internal passages in the transmission housing. The pressurized oil flows out of the internal passages in the transmission housing into clutch solenoid modulating valves (5-10). Number 3 clutch solenoid (9) is energized because the transmission is in neutral. None of the remaining clutch solenoid modulating valves (5), (6), (7), (8) and (10) provide oil to the transmission clutches. The pressurized oil leakage drains to oil sump (14) .The transmission hydraulic control relief valve (1) sends P3 converter inlet oil to torque converter (2). Torque converter outlet oil flows to oil cooler (16). After the oil cools, the oil flows to the transmission for transmission lubrication (15). After the transmission is lubricated and cooled the oil drains to the oil sump (14) .Torque converter inlet relief valve (12) limits P3 torque converter inlet oil pressure to a maximum of 900 70 kPa (130 10 psi). Torque converter inlet relief valve (12) is located in the torque converter housing. Transmission hydraulic control relief valve (1) must be removed in order to attain access to torque converter inlet relief valve (12) .Shifting the Transmission to the FIRST SPEED FORWARD position
Illustration 3 g00666329
The transmission hydraulic control in the FIRST SPEED FORWARD position and the engine is running. (1) Transmission hydraulic control relief valve (2) Torque converter (3) Flow control orifice (4) Transmission oil filter (5) Clutch solenoid modulating valve for the Number 1 clutch (6) Clutch solenoid modulating valve for the Number 4 clutch (7) Clutch solenoid modulating valve for the Number 2 clutch (8) Clutch solenoid modulating valve for the Number 5 clutch (9) Clutch solenoid modulating valve for the Number 3 clutch (10) Clutch solenoid modulating valve for the Number 6 clutch (11) Transmission oil pump (12) Torque converter inlet relief valve (13) Suction screen and magnet (14) Oil sump (15) Transmission lubrication (16) Oil cooler (A) Pump pressure tap at the transmission hydraulic control relief valve (B) P3 Torque converter inlet pressure tap (C) Torque converter outlet pressure tap (D) Pump pressure tap at the oil filter (F) Sampling valve for the transmission oil (G) Number 1 clutch pressure tap (H) Number 4 clutch pressure tap (J) Number 2 clutch pressure tap (K) Number 5 clutch pressure tap (L) Number 3 clutch pressure tap (M) Number 6 clutch pressure tap (N) Transmission lubrication pressure tap (AA) Pressure oil (BB) P3 Torque converter inlet pressure (CC) Torque converter outlet pressure (DD) Lubrication pressure (EE) Return oilThe power train electronic control module (ECM) modulates