VALVES KIT 5A9159 - Caterpillar

The bucket tilt (1) enables the bucket to be tilted horizontally to improve versatility. The bucket will tilt to the left when hydraulic oil enters port (6). The oil flows into passage (5) and to the motor (8). Relief valve (2) relieves excessive pressure to passage (3).The return oil flows through passage (3) and out of port (7).The bucket will tilt to the right when hydraulic oil enters port (7). The oil flows into passage (3) and to motor (8). Relief valve (4) relieves excessive pressure to passage (5).The return oil flows through passage (5) and out of port (6).Overload Warning System (If Equipped)
Introduction
Illustration 3 g03391421
Safe load switch / warning indicator location
(A) Safe load indicator switch
(B) Warning light When the operator turns safe load indicator switch (A) to the ON position, the overload warning system is activated. When the machine is lifting an object that is too heavy, warning light (B) will turn on and an alarm will sound.Schematic
Illustration 4 g03387459
Partial schematic (boom down and stick out)
(1) Pressure sensor
(2) Boom lowering control valve
(3) Relief valve
(4) Line
(5) Boom cylinder
(6) Valve
(7) Stick lowering control valve
(8) Relief valve
(9) Line
(10) Stick cylinder
(11) Valve
(12) Check valve
(13) Check valve
(14) Line
(15) Line
(16) Line
(17) Line
(18) Boom control valve
(19) Stick control valve
(20) Main control valve
(21) Line (pilot)
(22) Line (pilot)
(23) Slow return check valve
(24) Line (pilot)
(25) Line (pilot)
(26) Pilot control valve
(27) Pilot control valve
(28) Line (pilot)
(29) Line (pilot)
(30) Pilot manifold
(31) Main pump
(32) Hydraulic tank
(33) Oil distribution block Boom Circuit
Boom Lower
Pilot oil flows from pilot manifold (30), into distribution block (33) and into pilot control valve (26). When the operator moves the joystick to the boom LOWER position, pilot oil is sent through line (24) and line (21). Pilot oil inside line (21) flows into boom lowering control valve (2), through check valve (12) and shifts valve (11) to the left. This action allows the high-pressure oil in the rod end of boom cylinder (5) to return through boom control valve (2). Pilot oil inside line (24) flows into main control valve (20) and shifts boom control valve (18) upwards. This action allows the main pump oil to enter the head end of boom cylinder (5). The