GEAR-PLANET 1G5412 - Caterpillar

Illustration 1 g00515632
Operator's View of Travel Levers and Pedals (1) Left travel lever and pedal (2) Right travel lever and pedalThe travel lever and pedal consists of a combined hand lever and foot pedal. The left travel lever and pedal controls the left travel motors. The right travel lever and pedal controls the right travel motors. Pushing a travel lever and pedal forward actuates travel toward the idlers. Pulling a travel lever and pedal rearward actuates travel toward the sprockets. Each travel lever and pedal operates an individual travel pilot valve.
Illustration 2 g00515634
View of the Travel Pilot Valve From the Area Under the Cab Floor (3) Line (drain) (4) Line (pilot oil) (5) Line (travel control valve) (6) Line (travel control valve) (7) Travel pilot valve (right) (8) Travel pilot valve (left) (9) Line (pilot oil) (10) Line (drain) (11) Line (travel control valve) (12) Line (travel control valve)
Illustration 3 g00515637
Typical Travel Pilot Valve (13) Travel lever and pedal (14) Pedal (15) Rod (16) Seat (17) Spring (18) Metering spring (19) Spool (20) Passage (21) Passage (22) Spring (23) Spool (24) Return port (25) Return chamber (26) Passage (27) Passage (28) Pilot oil port (29) Passage (30) Port (31) Return passage (32) Passage (33) Passage (pilot oil supply) (34) PortNote: Operation of the travel pilot valve in the REVERSE position and FORWARD position are similar.When travel lever and pedal (13) is moved to the FORWARD TRAVEL position, pedal (14) pushes down on rod (15) and seat (16). Seat (16) pushes against the force of spring (17) and metering spring (18). The force of spring (18) moves spool (19) down opening passage (20) .As passage (20) opens, oil flows from pilot oil port (28) through passage (33), passage (31) and port (30). Oil flows from passage (31) through port (30) to the travel control valve stems in the travel, bottom dump and crossover control valve. The pressure of the oil on the ends of the travel control valve stems causes the travel control valve stems to move into a forward travel position. The oil from the chamber at the opposite end of the travel control valve stems comes back through port (34), through passage (29), passage (32), passage (27), and passage (26). The oil now flows into return chamber (25) and back to the hydraulic tank through port (24). A small movement of the travel lever and pedal (13) is used to inch the machine. A small movement of travel lever and pedal (13) moves rod (15) and seat (16) downward. Moving seat (16) causes spring (18) to push spool (19) downward. Passage (20) opens and oil pressure increases at port (30). If the force from the oil pressure is more than the force of spring (18), spool (19) moves up opening passage (20) to return chamber (25). The oil from port (30) goes through passage (21), passage (31), and passage (20) into return chamber (25). The oil pressure slightly decreases. Spool (19) is now held in a balance between the force