Service Repair Manual
120H NA Motor Grader
Product: MOTOR GRADER
Model: 120H NA MOTOR GRADER 4MK
Configuration: 120H Motor Grader 4MK00001-UP (MACHINE) POWERED BY 3116 Engine
Disassembly and Assembly
120H & 135H MOTOR GRADERS MACHINE SYSTEM
Media Number -SENR8544-01
Publication Date -01/10/2004
Date Updated -04/02/2016
Implement Control Valves
SMCS - 5051-016; 5051-011; 5051-012; 5051-015
Remove Implement Control Valves
1. Release the pressure in the hydraulic system as follows:
At operating temperature, the hydraulic oil is hot and under pressure.
Hot oil can cause burns. Sudden movement of the machine or release of
oil pressure can cause injury to persons on or near the machine. To
prevent possible injury, perform the following procedure before
working on the hydraulic and steering systems.
a. Move the machine to a smooth horizontal location. Move away from working machines and
personnel. Lower all implements to the ground. Install the wheel lean pin in front axle.
b. Permit only one operator on the machine. Keep all other personnel either away from the
machine or in view of the operator.
c. Activate the parking brake. Place all implements on the ground and put the blade in the
d. Stop the engine.
e. Turn the steering wheel back and forth several times to relieve pressure in the steering
f. Carefully loosen the filler cap on the hydraulic tank to release pressure in the tank.
120H Motor Grader 4MK00001-UP (MACHINE) POWERED BY 3116 Engine(SEBP...
g. Be sure all hydraulic pressure is released before any fitting, hose, or component is loosened,
tightened, removed or adjusted.
h. Tighten the cap on the hydraulic tank.
i. The pressure in the hydraulic system must be released before lines or components can be
Hydraulic pressure can exist in the hydraulic lines between the control
valves and the cylinders with the