GOVERNOR GP-WOODWARD 2795627 - Caterpillar

Tilt Control Valve HOLD Position
The control valve for tilt is the next control valve in the bank valve. When the engine is running, oil flows from the pump to the inlet for the tilt control valve. Then, the oil flows through the lift control valve into inlet (24). Inlet (24) is a common passage that extends through all control valves in the bank valve. Then, the oil flows into passage (32) .If the tilt control lever is in the HOLD position, the oil flows around valve spool (29) and into passage (30). Finally, the oil flows into passage (33) and to the auxiliary valve. If the auxiliary valve is also in the HOLD position, the oil flows through the auxiliary valve and returns to the hydraulic tank.In the HOLD position, tilt valve spool (29) blocks the flow of oil in port (19) and port (20). When the flow of oil to the tilt cylinder stops, the cylinder cannot move. The cylinder cannot move until the control lever is moved to either the TILT position or the DUMP position.When pilot oil is not routed to the spool, spring (28) (29) and spring (34) keep the spool in the centered position.Tilt Control Valve TILT Position
When the control lever is moved to the TILT position, pilot oil flows from the pilot control valve and to port (26). When, pilot oil pushes against valve spool (29) with greater force than spring (34) the spool moves to the right.When valve spool (29) moves to the right into the TILT position, oil flow from passage (32) into passage (30) and passage (33) is blocked. The increase in oil pressure in passage (24) opens check valve (23). When the check valve opens, the pump oil in passage (24) flows into passage (22) and out port (19). The oil then flows to the head end of the tilt cylinder.The pump oil flows into the head end of the tilt cylinder which forces the rod to extend. Then, the rod extends which causes the bucket to tilt back. Return oil from the rod end of the cylinder flows through port (20) and then through passage (31) to the filter and the tank.Some of the oil in passage (32) flows to the auxiliary main control valve. This flow allows some auxiliary movement of the auxiliary implement. As the need for oil in the tilt cylinder decreases, more oil is available to the auxiliary control valve.Tilt Control Valve DUMP Position
When the control lever is moved to the DUMP position, pilot oil flows from the pilot control valve and into port (27). When the force of pilot oil on spool (29) exceeds the force of spring (28), spool (29) moves to the left.When valve spool (29) moves to the left into the DUMP position, oil flows from passage (32) into passage (30) and passage (33) is blocked. The increase in oil pressure in passage (24) opens check valve (23). When the check valve opens, the pump oil in passage