2. There are three ways to check the operation of the coolant pump when it is installed on the engine. If the pump is defective, it must be replaced with a new or remanufactured one.
3. With the engine running at normal operating temperature, compress the upper radiator hose. If the coolant pump is working, a surge of pressure will be felt when the hose is released.
Attention! Keep your hands away from the fan blades.
4. The coolant pump has an inspection hole. If there is a fault in the pump seal, coolant will leak from the hole (see illustration). In most cases, you will need a flashlight and a mirror to find the hole in the bottom of the coolant pump to check it.
7.4. Check for leaks through the check hole (indicated by an arrow)
5. If the coolant pump shaft bearings fail, a whining sound may be heard from the drive belt side when the engine is running. When the engine is off, wear on the shaft can be felt by rocking the pump pulley up and down. Don't confuse a slipping drive belt that causes a squealing sound with a bad coolant pump bearing.