Commander 2WD V8-4.7L VIN P Flex Fuel (2007)
Water Pump: Description and Operation
Pump-Water
Description
4.7L
A centrifugal water pump circulates coolant through the water jackets, passages, intake manifold, radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a single serpentine drive belt.
The water pump impeller is pressed onto the rear of a shaft that rotates in bearings pressed into the housing. The housing has two small holes to allow
seepage to escape. The water pump seals are lubricated by the antifreeze in the coolant mixture. No additional lubrication is necessary.
Both heater hoses are connected to fittings on the timing chain front cover. The water pump is also mounted directly to the timing chain cover and is
equipped with a non serviceable integral pulley.
Operation
WATER PUMP
LOOSE IMPELLER - 3.7L/4.7L/5.7L ENGINES
NOTE: Due to the design of the 3.7/4.7L/5.7L engine water pumps, testing the pump for a loose impeller must be done by verifying coolant flow
in the radiator. To accomplish this refer to the following procedure.
DO NOT WASTE reusable coolant. If solution is clean, drain coolant into a clean container for reuse.
1. Drain coolant until the first row of cores is visible in the radiator.
2. Leaving the radiator cap off, start the engine. Run engine until thermostat opens.
3. While looking into the radiator through the radiator fill neck, raise engine rpm to 2000 RPM. Observe the flow of coolant from the first row of
cores.
4. If there is no flow or very little flow visable, replace the water pump.
INSPECTING FOR INLET RESTRICTIONS
Inadequate heater performance may be caused by a metal casting restriction in the heater hose inlet.
DO NOT WASTE reusable coolant. If solution is clean, drain the coolant into a clean container for reuse.
WARNING: Do not loosen the radiator draincock with the system hot and under pressure. Serious burns from the coolant can occur.
1. Drain sufficient coolant from the radiator to decrease the level below the heater hose inlet. On 4.7L engines this requires complete draining.
2. Remove the heater hose.
