Operation and maintenance manual

Cooling Fan Belt Tensioner QSB4.5 and QSB6.7
Page A-12 Section A - Adjustment, Repair, and Replacement
Install
CAUTION
Always use the correct thermostat and do not operate
the engine without a thermostat installed. The engine
can overheat if operated without a thermostat
because the path of least resistance for the coolant is
through the bypass to the pump inlet. An incorrect
thermostat can cause the engine to overheat or run
too cold.
NOTE: If a previously installed thermostat is being used,
make sure a new thermostat seal is used.
Install the thermostat into the thermostat housing.
Install the water outlet connection and mounting
capscrews.
Tighten the capscrews.
Torque Value: 10 N•m [ 89 in-lb ]
Cooling Fan Belt Tensioner
Maintenance Check
With the engine stopped, check the tensioner arm, pulley,
and stops for cracks. If any cracks are found, the
tensioner must be replaced.
With the belt installed, verify that neither tensioner arm
stop is in contact with the spring case stop. If either of the
stops is touching:
• Verify the correct belt part number is installed.
• If the correct belt is installed, replace the belt. Refer to
Procedure 008-002 in Section A.
After replacing the belt, if the tensioner arm stops are still
in contact with the spring case stop, replace the tensioner.