BEARING 1615808 - Caterpillar

Illustration 1 g01276251
Hydraulic schematic for the steering system (1) Steering cylinder (2) Steering cylinder (3) Steering cylinder crossover relief valve (4) Steering cylinder crossover relief valve (5) Brake release cylinder (6) Brake release cylinder pressure tap (7) Steering control valve (8) Steering release diverter valve (9) STIC steering pilot valve (10) Check valve (11) Line to parking brakes (12) Secondary steering diverter valve (13) Secondary steering pump (14) Brake release sequence valve (15) Steering system pressure tap (16) Spool (17) Implement and steering solenoid valve (18) Selector and pressure control valve (19) Parking brake control valve (20) Line from implement lift circuit (21) Check valve (22) Hydraulic oil cooler (23) Primary steering flow switch (24) Steering neutralizer valve for a right turn (25) Check valve (26) Pilot oil pressure tap (27) Check valve (28) Steering neutralizer valve for a left turn (29) Check valve (30) Line to parking brakes (31) Steering pump (32) Steering dual pilot check valve (33) Breaker relief valve (34) Pilot oil pressure reducing valve (35) Portable hydraulic pump quick connect coupler (36) Hydraulic tank (37) Pilot and Braking pump (38) Hydraulic filters (39) Portable hydraulic pump quick connect coupler (40) Line to brake accumulator charging valveThe optional secondary steering system has two purposes:
To supply steering oil should steering pump (13) fail or the engine stops while the machine is moving.
To add oil to the steering pump flow when the engine rpm is low and the machine is moving.Secondary steering pump (13) is mounted to the front of the output transfer gears. The secondary steering pump is a ground speed driven pump that turns as long as the machine is moving.With the engine running, oil from steering pump (31) flows through primary steering flow switch (23) to secondary steering diverter valve (12) . Oil from steering pump (31) moves the paddle in primary steering flow switch (23) . When the paddle moves, the contacts in primary steering flow switch (23) will close and the primary steering indicator will be off. Oil then flows through secondary steering diverter valve (12) to steering control valve (7) . This oil is used to operate steering cylinders (1) and (2) .If there is a failure of steering pump (31) there will be a loss of steering oil flow. The contacts in primary steering flow switch (23) will open. A signal will be sent to the primary steering indicator. The primary steering indicator will be on and alert the operator that the primary steering system has failed.When the machine starts to move, secondary steering pump (13) also starts to turn. As the pump turns it draws oil from hydraulic tank (36) and supplies oil to secondary steering diverter valve (12) .When the engine rpm is less than