Water Temperature Sending Unit

(2) Suspend a reliable thermometer in the water

(1) Drain a sufficient amount of coolant from the

so the sensitive portion does not rest directly on the

radiator to bring the level below that of the thermostat

container bottom or sides.

housing.

(3) Place the container on a stove or other heat

(2) Remove the 2 screws and lockwasher attaching

source. Stir the water occasionally for even heating.

the outlet tube to the thermostat housing and move

(4) In the temperature range of 166F to 165F

the tube from the housing.

the thermostat should start to open and should be

b. Testing.

completely open when the temperature is between

185F and 190F.

(5) Lifting the thermostat into the colder tem-

perature of the surrounding air should cause a pro-

nounced closing action within a short time.

(6) Discard a thermostat that fails to pass the

above test.

c. Installation. Reverse procedure in a above.

Attach the outlet tube securely and check for leaks

with the engine operating.

2-29. Water Temperature Sending Unit

a. Inspect. Check to see if coolant is leaking around

sending unit. Run engine for ten minutes and see if

water temperature dial shows an increase in tem-

perature. If not, sending unit is probably defective.

Replace a defective unit.

b. Removal. Refer to figure 2-23 and remove the

water temperature sending unit as follows :

(1) Drain a sufficient amount of coolant from the

radiator to bring the level below that of the water

temperature sending unit.

ME 3930-618-20/2-24

(2) Disconnect wire going to unit.

Figure 2-24. Testing thermostat (typical).

(34 Remove water temperature sending unit.

c. lnstallation. Reverse procedure in a above.

(1) Fill a container with sufficient water to cover

Inspect for leaks.

the thermostat.

2-30