PLATE-WEAR 1268343 - Caterpillar

Boom Raise
Illustration 1 g03724402
Typical of boom system with equipped with VA boom
(1) Boom cylinders
(2) Lowering control valve
(3) VA boom control valve
(4) VA boom pilot pressure sensor "B"
(5) Boom pilot pressure sensor "B"
(6) Boom control valve
(7) Boom down pressure sensor
(8) Boom pilot pressure sensor "A"
(9) Pilot pump
(10) Implement pump
(11) Hydraulic oil tank
(12) Unloading valve
(13) Pilot manifold
(14) Implement lockout solenoid
(15) Right-hand joystick
(16) Boom down pilot pressure switch
(17) VA boom pilot pressure sensor "A"
(18) VA boom control
(19) VA boom and lowering control valve
(20) Lowering valve spool When the right-hand joystick (15) is moved to the raise position pilot oil, from the pilot pump (9), flows to the boom control valve (6). The pilot oil over comes the spring on the control valve (6), oil flows from the implement pump (10) to the lowering control valves (2) . The oil flows through the check valves on the lowering control valves (2) and in to the head end of the boom cylinders (1). The cylinders to extend and raise the boom. Oil in the rod end of the cylinder returns to the hydraulic oil tank (11).Boom Lower
Illustration 2 g03727650When the right-hand joystick (15) is moved to the lower position pilot oil, from the pilot pump (9), flows to the control valve (6) and to the lowering control valve (2). The pilot oil over comes the spring on the boom control valve (6). Oil flows from the implement pump (9) to the rod end of the boom cylinders (1). The cylinders (1) are retracted causing the boom to lower. The pilot oil also shifts the spools (20) of the lowering control valve (2) allowing oil to return to the hydraulic oil tank 11.