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Chapter 8 - caterpillar engine and related systems – Cub Cadet 4 x 4 Volunteer User Manual

Page 252

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Chapter 8 - Caterpillar Engine and Related Systems

248

9c. Use the non-contact thermometer to moni-

tor the temperature in two spots as the
engine warms-up from a cold start:
Check the engine block adjacent to the
water pump.
Check the to-radiator pipe.
See Figure 8.72.

9d. Interpretation:

If the two temperatures follow each-other
closely, the thermostat has been removed or has
failed in the open position.

If the block temperature steadily rises past 160
deg.f. (71 deg.c.), and the temperature in the
pipe does not make a rapid shift upward, the
thermostat has failed in the closed position or
coolant is not circulating because of some other
problem (belt, water pump, obstruction).

If the block temperature rises to nearly 160 deg.
f. (71deg.c.) and the to-radiator pipe remains
cool until that point then suddenly rises to the
same temperature, the thermostat is operating
correctly.

NOTE: The thermostat opens at 167 deg. f. (75
deg.c.), but the insulating properties of the metal
reduce the surface reading. There is a weep
hole in the body of the thermostat to allow some
movement of coolant, even when the thermostat
is closed. See Figure 8.73.

NOTE: The correct direction for thermostat
installation is with the copper-colored wax-stat
section facing into the water jacket of the engine.
If installed wrong-way-round it will not open at
the correct temperature. See Figure 8.74.

Figure 8.72

Figure 8.73

Weep hole

Figure 8.74

Thermostat
housing

NOTE:
correct
positioning
of the
thermostat