TM 5-3805-263-14&P-3
SYSTEMS OPERATION
When the steering wheel is turned counterclockwise for
pressure setting of the relief valve. When the control
a left turn, the method of the flow of oil through the
valves for the implements are not being used, the
metering valve is like the description for the flow of oil for
pressure of the oil in lines (12) and (13) is 2150 psi(151.1
a right turn. For a left turn, the parts in the metering
kg/cm2).
valve and the flow of oil through the valve, and through
openings (10) and (11), are opposite to when a right turn
When the engine is running and the implements are not
is made.
being used, the pressure of the pump oil in lines (12 and
13) to the implement valves is approximately 2150 psi
There is a relation between the rpm the steering wheel is
(151.1 kg/cm2). The oil in lines ( I I ), (10) and (8) and in
turned and the time for the wheels to move to the
passage(23)is open to the tank and the pressure of the
position to make the turn. To make a fast turn, it is
oil in these lines is the same as the oil in the tank. Lock
necessary to turn the steering wheel fast (more rpm).
check valve (3) stops the oil in the lines between valve
(3) and cylinder (4) and the rod in the cylinder can not
Steering the machine with the engine stopped can be
move. The pressure of the oil in line (14) is the same as
done when the machine is moving. Much force is
the oil in lines (11), (10) and (8) and in the tank.
needed to turn the steering wheel and the result is a slow
turn.
When the blade lift lever, for the cylinder on the right
side, is held in the LOWER position, the pump oil in line
IMPLEMENT SYSTEM
(1 2) goes through implement valve (2), through line ( I 1)
When the engine is running, the oil from the pump goes
and lock check valve (3) into the head end of cylinder
through relief and pressure reduction valve (I), through
(4). The oil in the head of cylinder (4) pushes the piston
lines (1 2) and (13), to the control valves for the
and rod out of the cylinder which moves the blade down.
implements. The pressure of the
The pump oil through implement valve (2) to line (I11)
also
HYDRAULIC SYSTEM FOR LIFT CYLINDER
(Right side cylinder)
1. Relief and pressure reduction valve. 2. Implement valve to raise or lower the blade. 3. Lock check valve. 4. Lift
cylinder. 5 Blade float check valve. 6. Blade float pilot valve. 7. Passage for pump oil 8. Line for oil from the
implement valves. 9. Line for the oil from the other implement valves. 10. Line from implement valve to head end of
cylinder. 11. Line from implement valve to rod end of cylinder. 12. Line with pump oil to the implement valves 13. Line
with pump oil to other implement valves. 14. Line to shuttle valve in variable displacement pump. 15. Return line from
float pilot valve. 16. Pressure line to float pilot valve. 17. Pilot valve to LH float check 3-14 valve. 18. Pilot valve to RH
float check valve. 19 Implements valve manifold to and from float check valve. 20. Float check valve to lift cylinder head
end. 21. Float check valve to lift cylinder rod end. 22. Tank oil passage. 23. Tank oil pressure passage.
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