How to replace the auxiliary water pump

The cooling system of a car engine is designed to perform two functions. The first function is to maintain the operating and safe temperature of the engine for optimum combustion. The second function is intended for climate control in the car cabin at low ambient temperatures.

The water pump (auxiliary), or known as the auxiliary driven water pump, is the main water pump that is driven by an electric motor. The electric motor serves the same purpose as the drive or V-ribbed belt.

Having a water pump (auxiliary) and not having a belt drive, the pump allows the engine to have tremendous power. Since the pump pushes water through the galleries and hoses, the engine power is heavily stressed. Beltless water pump drive relieves extra load by increasing power at the wheels.

The disadvantage of the water pump (auxiliary) is the loss of electricity on the electric motor. In most vehicles equipped with an auxiliary water pump and disconnected from the mains, the red engine light comes on along with the yellow engine light. When the red engine light comes on, it means that something is seriously wrong and the engine may be damaged. If the light is on, the engine will only run for short periods of time, i.e. 30 seconds to 2 minutes.

Water pumps (auxiliaries) can fail in five different ways. If coolant is leaking from the outlet port, this indicates a dynamic seal failure. If the water pump leaks into the engine, it makes the oil milky and thin. The water pump impeller fails and makes a chirping sound when it contacts the housing. The passages in the water pump can become clogged due to sludge buildup, and if the electric motor fails, the water pump will fail.

Most people misdiagnose a milk oil problem when there is an internal water pump. They usually think that the head gasket has failed due to signs of low coolant levels and engine overheating.

Some other common symptoms include heater fluctuating heat, heater not heating at all, and window defrost not working.

Engine light codes associated with water pump failure:

R0125, R0128, R0197, R0217, R2181.

• Attention: Some vehicles have a large timing cover and a water pump attached to it. The timing case cover behind the water pump can crack, causing the oil to become cloudy. This can lead to misdiagnosis.

Part 1 of 4: Checking the condition of the water pump (auxiliary)

Necessary materials

• Coolant pressure tester
• flashlight
• Safety glasses
• Water and soap dispenser

Step 1: Open the hood in the engine compartment. Take a flashlight and visually inspect the water pump for leaks or external damage.

Step 2: Pinch the top radiator hose. This is a test to see if there is pressure in the system or not.

• AttentionA: If the upper radiator hose is hard, you need to leave the car's cooling system alone for 30 minutes.

Step 3: Check if the upper radiator hose is compressing.. Remove the radiator or reservoir cap.

• A warning: Do not open the radiator cap or reservoir on an overheated engine. The coolant will start to boil and splatter all over the place.

Step 4 Purchase a coolant test kit.. Find suitable attachments and attach the tester to a radiator or tank.

Inflate the tester to the pressure indicated on the cap. If you don't know the pressure, or no pressure is displayed, the system default is 13 psi (psi). Let the pressure tester hold the pressure for 15 minutes.

If the system holds pressure, then the cooling system is sealed. If the pressure drops slowly, check the tester to make sure it's not leaking before jumping to conclusions. Use a spray bottle with soap and water to spray the tester.

If the tester is leaking, it will bubble. If the tester does not leak, spray liquid on the cooling system to find the leak.

• Attention: If the dynamic seal in the water pump has a small invisible leak, connecting a pressure gauge will detect the leak and may cause a massive leak.

Part 2 of 4: Replacing the Water Pump (Auxiliary)

Necessary materials

• Hex key set
• socket wrenches
• Switch
• Camshaft locks
• Coolant drain pan
• Coolant resistant gloves
• Coolant resistant silicone
• 320-grit sandpaper
• flashlight
• Jack
• Harmonic balancer puller
• Jack stands
• Large flat screwdriver
• Wide choice
• Leather type protective gloves
• Lint-free fabric
• Oil drain pan
• Protective clothing
• Spatula / scraper
• Ratchet with metric and standard sockets
• Safety glasses
• V-ribbed belt removal tool
• Wrench
• Screw bit Torx
• Wheel chocks

Step 1: Park your vehicle on a level, firm surface.. Make sure the transmission is in park (for automatic transmission) or 1st gear (for manual transmission).

Step 2: Install wheel chocks around tires.. In this case, the wheel chocks wrap around the front wheels because the rear of the car will be raised.

Apply the parking brake to block the rear wheels from moving.

Step 3: Raise the car. Jack up the vehicle at the indicated points until the wheels are completely off the ground.

Step 4: Install Jacks. The jack stands should be located under the jacking points.

Then lower the car onto the jacks. In most modern cars, the jack stand attachment points are on a weld right under the doors along the bottom of the car.

Step 5: Remove coolant from the system. Take a coolant drain pan and place it under the radiator drain cock.

Drain all coolant. Once coolant stops flowing from the drain cock, close the drain cock and place a pan under the water pump area.

On a rear wheel drive vehicle with a water pump (auxiliary):

Step 6: Remove the lower radiator hose from the radiator and water pump.. You can rotate the hose to remove it from the mounting surfaces.

You may need to use a large pick to free the hose from the mounting surfaces.

Step 7. Remove poly V-belt or V-belt.. If you need to remove the V-ribbed belt to get to the electric motor, use a breaker to loosen the belt.

Remove the serpentine belt. If you need to remove the V-belts to get to the motor, loosen the adjuster and loosen the belt. Remove the V-belt.

Step 8: Remove heater hoses. Remove the heater hoses going to the water pump (auxiliary), if any.

Discard the heater hose clamps.

Step 9: Remove the bolts securing the water pump (auxiliary) motor to the motor.. Use the broken bar and remove the mounting bolts.

Take a large flathead screwdriver and move the motor slightly. Disconnect the wiring harness from the motor.

Step 10: Remove mounting bolts. Use a broken bar and remove the water pump (auxiliary) bolts from the cylinder block or timing cover.

Use a large flathead screwdriver to pry out the water pump.

On front-wheel drive vehicles with a water pump (auxiliary):

Step 11: Remove the engine cover if there is one..

Step 12 Remove the tire and wheel assembly.. Remove it from the side of the vehicle where the water pump (auxiliary) is located.

This will give you room to work under the car as you reach over the fender to access the water pump and electric motor bolts.

Step 13: Remove the lower radiator hose from the radiator and water pump.. You can rotate the hose to remove it from the mounting surfaces.

You may need to use a large pick to free the hose from the mounting surfaces.

Step 14. Remove poly V-belt or V-belt.. If you need to remove the serpentine belt to get to the electric motor, use the serpentine belt removal tool to loosen the serpentine belt.

Remove the serpentine belt. If you need to remove the V-belts to get to the motor, loosen the adjuster and loosen the belt. Remove the V-belt.

Step 15: Remove heater hoses. Remove the heater hoses going to the water pump (auxiliary), if any.

Discard the heater hose clamps.

Step 16: Remove mounting bolts. Reach through the fender and use a crowbar to loosen the water pump motor (auxiliary) mounting bolts.

Take a large flathead screwdriver and lift the motor slightly. Disconnect the wiring harness from the motor.

Step 17: Remove mounting bolts. Use a broken bar and remove the water pump (auxiliary) bolts from the cylinder block or timing cover.

You may need to put your hand through the fender to unscrew the mounting bolts. Use a large flathead screwdriver to pry out the water pump once the bolts are removed.

On rear-wheel drive vehicles with a water pump (auxiliary):

• Attention: If the water pump has an o-ring as a seal, install only a new o-ring. Do not apply silicone to the O-ring. Silicone will cause the O-ring to leak.

Step 18: Apply Silicone. Apply a thin coat of coolant resistant silicone to the water pump mounting surface.

Also, apply a thin coat of coolant resistant silicone to the water pump mounting surface on the cylinder block. This helps seal the gasket in the coolant and prevents any leaks for up to 12 years.

Step 19: Install a new gasket or o-ring to the water pump.. Apply coolant resistant silicone to the water pump mounting bolts.

Place the water pump on the cylinder block or timing cover and tighten the mounting bolts by hand. Tighten the bolts by hand.

Step 20: Tighten the water pump bolts as recommended.. Specifications should be found in the information provided when purchasing the water pump.

If you don't know the specs, you can tighten the bolts to 12 ft-lbs and then tighten to 30 ft-lbs. If you do this step by step, you will be able to secure the seal properly.

Step 21: Install this harness to the motor.. Place the motor on the new water pump and tighten the bolts to specification.

If you don't have any specifications, you can tighten the bolts up to 12 ft-lbs and an additional 1/8 turn.

Step 22: Attach the lower radiator hose to the water pump and radiator.. Make sure you use new clamps to keep the hose tight.

Step 23: Install the drive belts or V-ribbed belt if you had to remove them.. Make sure you set the tension on the drive belts to match their width or 1/4" gap.

On front-wheel drive vehicles with a water pump (auxiliary):

Step 24: Apply Silicone. Apply a thin coat of coolant resistant silicone to the water pump mounting surface.

Also apply a thin coat of coolant resistant silicone to the water pump mounting surface on the cylinder block. This helps seal the gasket in the coolant and prevents any leaks for up to 12 years.

• Attention: If the water pump has an o-ring as a seal, install only a new o-ring. Do not apply silicone to the O-ring. Silicone will cause the O-ring to leak.

Step 25: Install a new gasket or o-ring to the water pump.. Apply coolant resistant silicone to the water pump mounting bolts.

Place the water pump on the cylinder block or timing cover and tighten the mounting bolts by hand. Reach your hand through the fender, tighten the bolts.

Step 26: Tighten the water pump bolts.. Reach your hand through the fender and tighten the water pump bolts to the specifications in the information that came with the pump.

If you don't know the specs, you can tighten the bolts to 12 ft-lbs and then tighten to 30 ft-lbs. If you do this step by step, you will be able to secure the seal properly.

Step 27: Install this harness to the motor.. Place the motor on the new water pump and tighten the bolts to specification.

If you don't have any specifications, you can tighten the bolts up to 12 ft-lbs and 1/8 turn more.

Step 28: Attach the lower radiator hose to the water pump and radiator.. Make sure you use new clamps to keep the hose tight.

Step 29: Install the drive belts or V-ribbed belt if you had to remove them.. Make sure you set the tension on the drive belts to match their width or 1/4" gap.

• Attention: If the water pump (auxiliary) is installed in the engine block behind the front cover, you may have to remove the oil pan to remove the front cover. If you need to remove the engine oil pan, you will need a new oil pan and a new oil pan gasket to drain and seal the engine oil pan. After installing the engine oil pan, be sure to fill the engine with new engine oil.

Part 3 of 4: Filling and Checking the Coolant System

Required material

• Coolant
• Coolant pressure tester
• New radiator cap

Step 1: Fill the cooling system with what the dealer recommends. Let the system burp and continue to fill until the system is full.

Step 2: Take a coolant pressure tester and place it on the radiator or reservoir.. Inflate the tester to the pressure indicated on the cap.

If you don't know the pressure, or no pressure is displayed, the system default is 13 psi (psi).

Step 3: Watch the pressure tester for 5 minutes.. If the system holds pressure, then the cooling system is sealed.

• Attention: If the pressure tester is leaking and you do not see any coolant leaks, you need to check the tool for leaks. To do this, take a spray bottle with soap and water and spray the tester. If the hoses are leaking, check the tightness of the clamps.

Step 4: Install a new radiator or reservoir cap.. Do not use an old cap as it may not hold proper pressure.

Step 5: Put on the engine cover if you had to remove it..

Step 6: Raise the car. Jack up the vehicle at the indicated points until the wheels are completely off the ground.

Step 7: Remove the jack stands and keep them away from the vehicle..

Step 8: Lower the car so that all four wheels are on the ground.. Pull out the jack and set it aside.

Step 9: Remove the wheel chocks.

Part 4 of 4: Test drive the car

Required material

• flashlight

Step 1: Drive the car around the block. While you are driving, check to see if the engine light comes on.

Also keep an eye on the cooling temperature to make sure it is working properly.

Step 2: Check for coolant leaks. When you're done with your test drive, grab a flashlight and look under the car for any coolant leaks.

Open the hood and check the water pump (auxiliary) for leaks. Also check the lower radiator hose and heater hoses for leaks.

If your vehicle is still leaking coolant or overheating, or the engine light comes on after replacing the water pump (auxiliary), the water pump (auxiliary) may need further diagnostics or an electrical problem. If the problem persists, you should seek the assistance of one of AvtoTachki's certified mechanics, who can inspect the water pump (auxiliary) and replace it if necessary.