Owner manual

Chapter 8 - Caterpillar Engine and Related Systems
239
• The vent point at the back of the system is a set-
screw at the highest point: the metal coolant
pipe that connects to the thermostat housing.
See Figure 8.52.
2h. Flow:
• With the thermostat closed, the water pump
does not circulate water.
• With the thermostat open, the water exits the
engine via the thermostat housing, to the upper
pipe.
• The coolant travels forward, and the pipes shift
from a vertical orientation (upper and lower) to a
horizontal (side-by-side) orientation. The upper
pipe becomes the inner pipe. See Figure 8.53.
Figure 8.52
Thermostat
housing
Vent
plug
Figure 8.53
To radiator
Return
• The coolant enters the top (rear) of the radiator,
on the left side. See Figure 8.54.
• The coolant exits the radiator at the bottom
(front) on the right side. See Figure 8.55.
• The coolant returns to the engine through the
lower/outer pipe.
Figure 8.54
Top (rear)
coolant hose
Radiator
Figure 8.55
Radiator seen
from bottom
Fan switch
Return hose