How to Repair a Radiator Water Pump

car Radiator
  • 2-6 hours
  • Intermediate
  • 50-125
What You'll Need
Water pump repair kit
Replacement seals and bearings
Impeller blades (optional)
Socket set

The radiator water pump is a motorized pumping device fitted inside the engine cooling system of automobiles. The radiator water pump is considered to be the heart of an engine cooling system, as it circulates water or coolant from radiator to engine and vice versa. A typical radiator water pump has a metal or plastic impeller with blades, which is attached to the shaft, and it is supported by bearings and seal assembly. The water pump derives its power from fan belt or the timing belt.

Internal combustion engines produce lot of heat while running, and if the engine temperature is not kept in check, the engine may seize or stop working. The radiator prevents this by circulating cool water or coolant around the engine. The coolant absorbs the heat, circulates back to the radiator, cools down, and is then pumped back to the engine. This cycle continues as long as the radiator pump is working. As soon as radiator water pump develops a problem, the temperature of engine increases, causing the engine to seize. Thus, it is imperative to keep the radiator water pump in a perfectly working condition.

Signs of Malfunctioning of the Radiator Water Pump

These are some tell-tale signs which might help you in resolving radiator water pump problems in the initial stages:

Screeching noise from the radiator (do not get it confused with engine noise)

The car leaves behind coolant or water spots where it has been parked, thus indicating leakage. It might be due to radiator water pump leakage or radiator pipe leakage.

Strong odor of coolant while driving.

Spike in engine temperature (indicated by temperature indicator on dash board)

Wobbling of radiator fan, which produces an odd noise while driving.

Sudden clunking noise from radiator indicating the impeller is broken

    If you come across any of the above-mentioned problems, it is time to check the radiator. Depending on the type of problem, you may be able to repair a radiator water pump on your own.

    Caveat: Allow the engine to cool down completely before you undertake the task of repairing a radiator water pump.

    A radiator water pump can only be repaired for minor problems, which include breaking of timing belt, broken impeller blades, cracking of seal, and damaged bearings.

    Step 1 – Remove Radiator Hose

    Once the engine has cooled down completely, check if the timing belt is intact. It is fairly easy to remove the timing belt and replace it with a new one. If the problem is not with the belt, then you will have to proceed further.

    Step 2 – Drain Out the Coolant

    Slide below the hood of the car, locate the petcock, unscrew it and drain the coolant into a plastic container.

    Step 3 – Remove the Fan Assembly

    Using a screwdriver and wrenches, remove the fan assembly, which includes the shroud, fan and fan belt

    Step 4 – Remove Water Pump

    Once the fan is removed, the water pump becomes visible. Remove it using a socket set.

    Step 5 – Repair the Pump

    After removing the pump, open its housing and check for cracked or damaged bearings or seals. Replace them appropriately and close the housing. If the impeller is broken, replace it properly.

    Step 6 – Reassemble the Cooling System

    After carrying out necessary repairs, reassemble every component that has been removed. Start the engine and keep it running for five minutes to make sure that everything is in order.