HOSE AS 3792214 - Caterpillar

Illustration 1 g00473427
(1) Left main control valve. (2) Right main control valve. (3) Makeup and vent valve. (4) Makeup and vent valve.
Illustration 2 g00473428
View A-AMakeup and Vent Valve (5) Vent to pilot control valve. (6) Spring. (7) Shoulder. (8) Passage to tank. (9) Passage from lift cylinder. (10) Valve.The makeup and vent valve that is in each main control valve is located in the rod end circuit of the lift cylinders. The venting function of this valve makes the FLOAT function of the bucket possible.When the lift control lever is placed into the FLOAT position, the pilot control valve causes oil to flow from vent hole (5). At the same time, pilot oil shifts the lift control valve spool. This allows supply oil to flow into the circuit that lowers the bucket. Supply oil is also in passage (9) .System pressure acts on shoulder (7) of valve (10). When the oil inside valve (10) is vented, the oil pressure against the shoulder overcomes the force of spring (6). Valve (10) moves up.When the valve is off of the seat, oil can flow to the hydraulic tank through passage (8). The weight of the lift arms and of the bucket causes the bucket to lower.