COVER 5S4492 - Caterpillar

Illustration 1 g00592997
(1) Cooler bypass and back pressure relief valve (2) Return line from rear control valve to the hydraulic tank (3) Return line from rear control valve to the hydraulic tank (4) Return line (case drain to the hydraulic tank) (5) Return line from the front return manifold to the hydraulic tank (6) Return line (return oil to hydraulic oil cooler) (7) Implement bypass relief valve (8) Cooler bypass valve
Illustration 2 g00593222
(9) Hydraulic oil cooler (10) Return line (return oil from hydraulic oil cooler) (11) Line (supply to hydraulic oil cooler) (12) Drain line from the fan motor
Illustration 3 g00593231
(1) Cooler bypass and back pressure relief valve (3) Return line from rear control valve to the hydraulic tank (7) Implement bypass relief valve (13) Passage (return oil from the implements to the oil cooler) (14) Spool (15) Spring (16) Adjusting screw (17) Passage (return oil from the swing and travel system) (18) Spool (19) Spring (20) ShimsReturn oil from the swing circuit and return oil from the travel circuit pass through passage (17) to cooler bypass and back pressure relief valve (1). When the swing and travel pressure in passage (17) increases to approximately 900 kPa (130 psi), spool (18) moves left compressing spring (19). The swing and travel return oil flows past spool (18) into passage (13). The force of spring (19) is adjusted with shims (20). The return oil for the swing circuit, the return oil for the travel circuit, and the return oil for the implement circuits are combined in passage (13). The combined flow is directed into one of two directions.
If cooler shutoff valve's check valve is closed, the combined return oil in passage (13) increases to approximately 400 kPa (58 psi). Spool (14) moves to the right and compressing spring (15). The combined oil flows past spool (14) into passage (3) and into the hydraulic tank.
If cooler shutoff valve's check valve is open, the combined return oil flow passes through the hydraulic oil cooler to the hydraulic tank.