Operation and maintenance manual

QSB4.5 and QSB6.7 Coolant Thermostat
Section A - Adjustment, Repair, and Replacement Page A-9
Finishing Steps
WARNING
Batteries can emit explosive gases. To reduce the
possibility of personal injury, always ventilate the
compartment before servicing the batteries. To avoid
arcing, remove the negative (-) battery cable first and
attach the negative (-) battery cable last.
WARNING
Acid is extremely dangerous and can damage the
machinery and can also cause serious burns. Always
provide a tank of strong soda water as a neutralizing
agent when servicing the batteries. Wear goggles and
protective clothing to reduce the possibility of serious
personal injury.
• Connect all wires to the alternator.
• Install the drive belt. Refer to Procedure 008-002 in
Section A.
• Connect the batteries. Refer to the OEM service
manual.
• Operate engine to check for proper operation.
Charge-Air Cooler
Maintenance Check
Inspect the charge-air cooler (CAC) for dirt and debris
blocking the fins. Check for cracks, holes, or other
damage. If damage is found, refer to the vehicle, vessel,
or equipment manufacturer.
Coolant Thermostat
General Information
The thermostat controls the engine coolant temperature.
When the coolant temperature is below the operating
range, engine coolant is bypassed back to the inlet of the
water pump. When the engine coolant temperature
reaches the operating range, the thermostat opens, seals
off the bypass, and forces engine coolant to flow to the
radiator or the heat exchanger.
NOTE: Some applications use an OEM supplied remote
mounted thermostat. Refer to the OEM service manual for
location. Refer to the OEM service manual for remote
mounted thermostat removal and installation instructions.
An incorrect or malfunctioning thermostat can cause the
engine to run too hot or too cold.