SHAFT-INPUT 3520386 - Caterpillar

Float Operation
When the bulldozer control lever is moved to Float detent position, lift valve spool (10) moves into the detent in bulldozer lift control valve (11). When lift valve spool (10) is in the Float position there is no signal oilpressure to the compensator valve. The signal oil to the compensator valve goes to tank through shuttle valves (32), (24), (12), and (2). Pump (39) destrokes and pump oil pressure is low.The rod and head ends of the lift cylinders are now open to tank through the common tank passages. With both ends of lift cylinders (20) open to tank, the cylinder rods can move freely in either direction according to theamount and direction of the force on the blade.The bulldozer control lever must be manually moved out of the Float detent position. There is no kickout for Float position.Bulldozer Tilt Circuit
Tilt Right Operation
When the bulldozer control lever is moved to Tilt Right position, tilt valve spool (4) moves to Tilt Right position. Cylinder oil from the rod end of the tilt cylinder goes through tilt valve spool (4) and becomes signal oil.Part of the signal oil goes to the spring chamber behind flow control valve (7) and moves it toward the right. The rest of the signal oil goes through shuttle valves (2), (12), (24) and (32) to compensator valve (34). Compensatorvalve (34) causes pump (39) to upstroke and increase the pump oil pressure to the margin pressure, approximately 2100 kPa (305 psi), above the signal oil pressure.The increased pump oil pressure goes through inlet manifold (38), priority flow control valve (31) and the parallel oil passages to flow control valve (7). Pump oil moves flow control valve (7) farther to the right andsends pump oil to load check valve (6). Load check valve (6) opens and pump oil goes around tilt valve spool (4) and out of bulldozer tilt control valve (3) to the rod end of tilt cylinder (5). The cylinder rod retracts andthe bulldozer blade tilts to the right.The movement of the cylinder rod pushes the oil out of the head end of the tilt cylinder. This return oil comes into the bulldozer control valve and goes around tilt valve spool (4). The return oil then goes through thecommon tank passages in the bulldozer tilt control valve, the bulldozer lift control valve, the ripper control valves and the steering control valve to the inlet manifold.From the inlet manifold, return oil goes to cooler bypass valve (40) and then part of the return oil goes to the oil cooler and the rest goes to filter (33) and back to tank (25). The return oil through the oil cooler goes throughthe pump and motor cases for cooling purposes and then to filter (29) and back to tank.When the bulldozer control lever is released, the lever and tilt valve spool (4) go back to their Hold positions. The tilt valve spool holds the oil in tilt cylinder (5). Movement of the cylinder rod stops. The bulldozerblade stays