How to replace a water pump – that’s how it’s done!

How to replace a water pump - that's how it’s done!

Water pump is an important component of the vehicle’s cooling circuit and is therefore crucial for its performance and service life. For this reason, you should react quickly if the water pump is damaged and replace it if necessary. We will show you what you need to pay attention to and what differences there are between the various water pumps.

Why is a water pump so important?

Why is a water pump so important

A water pump is responsible for the uninterrupted cooling circuit in water-cooled engine systems. It therefore transports the heated coolant from the engine block to the radiator and the cooled coolant back to the engine. If there are any interruptions in the cooling circuit, the engine gradually overheats, and this can lead to overheating and thus to permanent and extremely expensive damage to the engine. That is why you should always keep an eye on the functionality of the water pump.

Signs of defects in the water pump

Signs of defects in the water pump

There are various signs that indicate a defect in the water pump. These are among others:

loss of coolant in carThe loss of coolant. A slow or even a strong loss of coolant is always a sign of a defect in the cooling system. The coolant usually forms a puddle under the vehicle. However, this symptom may also indicate damage to the radiator, the cylinder head or the pipe system.
Distinct engine noisesDistinct noises. If mechanical damage to the water pump has occurred, this often becomes noticeable in the noise. A knocking, crunching or even grinding may be a sign of damage to the water pump. However, these sounds are usually only noticeable when the engine is running with the bonnet open.
increase in engine temperatureSignificant increase in engine temperature. If the cooling system fails due to the damage, the engine starts to overheat very quickly. Therefore, pay attention to the engine temperature display. As soon as it rises higher than usual, you should park the vehicle and check the cooling system, if possible.
car heater failsHeater fails. A heater failure may also indicate a fault in the cooling circuit. The vehicle should be parked as soon as possible, and repairs should be carried out in this case as well.

Possible damage to the water pump

Possible damage to the water pump

Usually it’s mechanical failures of the water pump that occur. As it is operating constantly, certain damage is not too rare. If you are lucky, only seal is affected, so the replacement can be done at little cost. Otherwise, the entire water pump should be removed and replaced. A repair is not possible for this component.

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Replacing the water pump: Workshop or DIY?

Replacing the water pump: Workshop or DIY?

Whether you should replace your defective water pump yourself or rather go to a workshop depends on various factors. On one hand, your experience in vehicle repairs certainly plays a role.

But the type of vehicle and the manufacturer can also have a considerable impact. In many models the water pump has to be installed at a certain angle and is very difficult to reach. In this case it is more effective to commission a specialist workshop to carry out the work. You can still reduce the cost of repairs by using your own spare parts.

1. The mechanical water pump

how to replace mechanical water pump

Mechanical water pumps are driven by a V-belt or a toothed belt. This coupling should initially be removed.

– First, the coolant should be drained from the cooling circuit
– Collect the coolant in a container for disposal
– It may be necessary to move the tension pulley to remove the V-belt or toothed belt
– The pulley should be unscrewed from the water pump
– All pipes and hoses attached to the water pump should be removed.
– Now the water pump can be removed
– Insert a new water pump
– Mount all cables and hoses and attach the pulley
– If it is driven by the toothed belt, consider the control times
– Fill in new coolant.

2. The electric water pump

how to replace electric water pump

With electric water pumps, replacement is much easier because they are not attached to V-belts or toothed belts.

– First, the coolant should be drained from the cooling circuit
– Collect the coolant in a container for disposal
– Remove all pipes and hoses attached to the water pump
– Replace the defective water pump with a new one
– Attach all cables and hoses
– Fill in new coolant

For both types of water pumps you should carry out a leak test after filling in new coolant. Also, the engine cooling system should be bled to ensure proper and permanent cooling. After the tests, the engine can be put back into permanent operation.

Overview of costs for replacing the water pump

costs for replacing the water pump in car

A specialist workshop usually estimates a good three hours of work for changing a water pump. However, if you do this work yourself, the only costs incurred are those for a new water pump. These are usually between 50 and 500 pounds.

The price fluctuation results from different prices for different car models, but also from fluctuating prices between original parts and branded spare parts. Thanks to prices for a water pump which are often quite low, it is almost always worth having the water pump replaced when a V-belt or timing belt is changed. The expenses therefore increase only slightly.

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Stay alert when replacing the water pump

Stay alert when replacing the water pump

As the water pump is particularly important for the engine’s durability and therefore for your vehicle, you should check its operation regularly. So, pay attention to the above-mentioned defect signs in the water pump. Also, you can do a lot to prolong the lifespan of your vehicle by carrying out repairs and maintenance. Here are some examples:

how to replace timing beltIf your vehicle has a mechanical water pump, you should always replace it directly when changing the timing belt. Although this will result in a slightly higher cost, it can prevent emergency repairs or damage to the engine due to overheating. As mechanical components are also subject to a certain amount of wear and tear, replacing the water pump is clearly worth it in such a case.
oem water pumpCompare the possible costs for a replacement model. Often you do not have to reply only on the vehicle manufacturer’s expensive water pumps, but you can use a branded spare part as well. This can significantly reduce the costs for the replacement.
dispose of used engine coolantRemember to collect the coolant and dispose of it in an environmentally friendly way. Violating these requirements can quickly become very expensive.
If you do not want to or cannot replace the water pump yourself, you should always ask for quotations from different workshops. It will also be cheaper if you order the required spare parts yourself.

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