Radiator Shutters - Komatsu 830E Shop Manual

The optional radiator shutters aid in maintaining proper
engine coolant temperature, primarily in cold climate
operations.
The shutter system contains the following components:
•
Shutter assembly with hydraulic control actuator
cylinder
•
Hydraulic oil supply pressure reducing valves and
cylinder control solenoid
•
Solenoid control relays
•
Shutter enable/disable switch
1. Radiator Shroud
2. Oil Supply
3. Pressure Reducing Valve
4. Pressure Reducing Valve
5. Shutter Solenoid Valve
6. To Cylinder Head End
7. To Cylinder Rod End
8. Electrical Harness (To RH
Frame Junction Box)
9. To Shutter Enable Switch
box)
10. Oil Return to Tank
Hose
11. Shutter Actuator
Cylinder
FIGURE 19-1. SHUTTER ACTUATOR CYLINDER OIL SUPPLY VALVES
M19002

RADIATOR SHUTTERS

Operation
Hydraulic Circuit
Hydraulic oil pressure to operate the shutter assembly
actuator cylinder is supplied from the truck steering cir-
cuit. A hose (2, Figure 19-1) attached to a "T" fitting at
the automatic lubrication system pump supply port
routes oil to the pressure reducing valve (3). This valve
reduces the steering circuit pressure, 3500 psi (24 132
kPa) to 1500psi (10 342 kPa). The pressure is further
reduced to 75 psi (517 kPa) by the pressure reducing
valve (4) which supplies the shutter solenoid valve (5)
to pressurize the head end of the shutter actuator cylin-
der (11), closing the shutters during engine warm-up.
When the shutters are signalled to open, the solenoid
valve will be de-energized and the spool will shift to
direct oil to the rod end of the actuator cylinder. Oil
returns to tank through the hose (10) routed to the
hydraulic tank.
Radiator Shutters M19-1