MOUNT 1423921 - Caterpillar

Straight Travel Control
Straight travel(tracking) can be maintained even though there is a swing or implement operation during travel. Make reference to the section, "Straight Travel" for systems operation.Straight Travel Operation
Main Control Valve Compartment
(1) Right travel control valve. (2) Straight travel control valve. (3) Left travel control valve.
Hydraulic Schematic(Partial)(Only Right And Left Travel Activated)
(1) Right travel control valve. (2) Straight travel control valve. (3) Left travel control valve. (4) Main control valves. (5) Line. (6) Line. (7) Upper pump. (8) Lower pump.When the upper structure or implements are operated while the machine is traveling, straight travel control valve (2) maintains straight travel of the machine.Straight travel control valve (2) also improves the control of operations such as pipe laying or placement of timbers. When the machine travels without a swing or implement operation, oil from upper pump (7) goes through right travel control valve (1) to the right travel motor. Oil from lower pump (8) goes through straight travel control valve (2) and left travel control valve (3) to the left travel motor. Because both travel circuits are separated, the machine continues to travel straight, unless a difference in travel resistance occurs between the right and left tracks.Without the straight travel system, a swing and/or implement operation (while performing a travel operation) would cause upper pump (7) and lower pump (8) to supply varying amounts of pump oil to the track motors. This would cause the right and left travel motors to rotate at different speeds which would result in the machine turning.The straight travel system controls the machine travel to provide straight travel when circuits other than the travel circuits are simultaneously operated. When straight travel control valve (2) is activated by pilot oil pressure, the following occurs: 1. Upper pump (7) supplies oil to the left travel circuit and to the right travel circuit to drive both motors in parallel.2. The swing and implement circuits get oil from the lower pump. When the machine is traveling, the swing and implement circuits do not require a large amount of flow. They are operated at speeds low enough to keep the machine stable. The remainder of the oil is shared by the right and left travel circuits.Implement And Travel Operation
Hydraulic Schematic(Partial)(Boom And Travel Activated)
(1) Parallel feeder passage. (2) Main control valves. (3) Stick I control valve. (4) Swing control valve. (5) Left travel control valve. (6) Center bypass passage. (7) Right travel control valve. (8) Bucket control valve. (9) Boom 1 control valve. (10) Center bypass passage. (11) Passage. (12) Passage. (13) Passage. (14) Passage. (15) Straight travel control valve. (16) Passage. (17) Passage. (18) Pilot passage. (19) Pilot passage. (20) Pilot passage. (21) Passage. (22) Passage. (23) Pilot passage. (24) Pilot passage. (25) Passage. (26) Parallel feeder passage. (27) Pilot oil manifold. (28) Upper pump. (29) Drain line. (30) Line. (31) Line. (32) Pilot pump. (33) Lower pump.When the boom control lever is operated during a travel operation, pilot oil from travel and boom pilot control valves goes