46
TK 61555-2-MM-EN
Figure 15.
Plastic Expansion Tank
1.
Float
2.
Coolant Level Switch
N
No
otte
e::
shows the expansion tank in two pieces. The two pieces are bonded
together when the tank is assembled, so it cannot be disassembled, but the coolant level
switch can be replaced.
Testing the Coolant Level Switch
Testing the switch in the unit is accomplished by adjusting the coolant level and also by
removing the expansion tank from the unit by flipping the tank upside down and right side up.
1.
Remove the wire harness connector from the coolant level switch.
2.
Use an ohmmeter to check the continuity of the switch at the connection pins.
3.
Verify the coolant level is above the switch and check the continuity of the switch. The switch
should be closed. If the tank was removed from the unit, accomplish this check with the tank
upside down.
4.
Drain coolant from the expansion tank until the coolant level is well below the switch level
and check continuity of the switch. The switch should be open. If the tank was removed from
the unit, accomplish this check with the tank right side up.
5.
Replace the switch if it is does not close in step 3 and does not open in step 4.
Checking the Float
The float is made of polypropylene foam. It is unlikely that the float would fail unless it sticks
inside the tank so it cannot move.
1.
Verify the coolant level is above the float.
2.
Slowly drain coolant from the expansion tank and watch the float. The float should drop with
the coolant level.
3.
If the float did not drop with the coolant level, remove the expansion tank from the unit.
4.
Flip the expansion tank upside down and right side up to see if the float moves inside the
expansion tank. Replace the expansion tank with a new one if the float is stuck or does not
move with the coolant level.
Replacing the Coolant Level Switch
1.
Disconnect the wire harness connector from the coolant level switch.
