HEAD ASSEM. 6N9974 - Caterpillar

Illustration 1 g01052268
Location of the Travel Control Valve
The rear of the machine
The travel control valve is mounted on the hydraulic tank at the rear of the machine.
Illustration 2 g02583837
Travel Control Valve
(1) Inlet section
(2) Pressure differential relief valve
(3) Left travel control valve
(4) Right travel control valve
(5) End section
(6) Main relief valve
(7) Proportional solenoid valve (reverse left)
(8) Proportional solenoid valve (forward left)
(9) Proportional solenoid valve (reverse right)
(10) Proportional solenoid valve (forward right)
(P1) Pump port
(T1) Tank port
(A) Forward port (left travel control valve)
(A) Forward port (right travel control valve)
(B) Reverse port (left travel control valve)
(B) Reverse port (right travel control valve)
Illustration 3 g01474093
Hydraulic Schematic of the Travel Control Valve
(1) Inlet section
(2) Pressure differential relief valve
(3) Left travel control valve
(4) Right travel control valve
(6) End section
(7) Main relief valve
(8) Proportional solenoid valve (reverse left)
(9) Proportional solenoid valve (forward left)
(10) Proportional solenoid valve (reverse right)
(11) Proportional solenoid valve (forward right)
(12) Orifice
(13) Orifice
(14) Signal duplication valve
(15) Back pressure valve
(16) Pressure compensator valve (left)
(17) Valve spool
(18) Pressure compensator valve (right)
(19) Valve spool When the travel pedals are not activated, pressure differential relief valve (2) increases the pressure oil from the main pumps at port (P1) to 4000 kPa (580 psi). The pressure differential relief valve is adjustable.The pumps of the Track Feller Bunchers are now split. One is for the implement circuit and another one is for the travel circuit. The pressure setting for the main relief valve is set at 35500 300 kPa (5149 44 psi) for the Implement valve. The pressure setting for the main relief valve is set at 35500 300 kPa (5149 44 psi) for the travel valve.Neutral Position
When the travel pedals are in the NEUTRAL position, the valve spools are in the CENTER position. Pressure compensator valve (16) and (18) contains a load hold check valve.Check valves in control valves (3) and (4) prevent cavitation in the travel circuit.The signal pressure oil drains from pressure compensator valve (16) and (18). Pressure differential relief valve (2) sets the signal pressure. Forward Travel
When the operator presses both travel pedals forward, a signal is sent from each