Replacing the water pump with the timing belt: when and why?

If you get a quote for a new timing belt, there is often a water pump on it as well. That is not an optional extra: on many engines the belt drives the pump and the pump sits behind the same cover. Below you can read when replacing the pump at the same time is needed, when it is not and how to tell that a water pump is failing.

By the team at Autobedrijf Willemsbrug, RDW-approved APK (MOT) test station since 1979 · Updated 6 November 2026

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The short answer

If the timing belt drives the water pump, the ANWB (the Dutch motoring organisation) and parts manufacturers advise replacing the pump at the same time as the belt. The pump wears at about the same rate, most of the work has already been done and a leaking pump can damage a new belt with coolant. If the pump is driven separately, by the auxiliary belt or electrically, it does not need to be replaced with the belt. We look up how it works on your engine from your registration number (kenteken) and tell you in advance whether the pump is in the price.

Timing belt service at Autobedrijf Willemsbrug: we look up the interval for your engine from your registration number and replace the belt with the tensioners and, if the belt drives it, the water pump. For the wet belt of the 1.0 and 1.2 PureTech we have fixed package prices. We tell you the price in advance and only do extra work with your approval. Call +31 10 479 00 00. Our team speaks English. More about timing belt replacement

When does the timing belt drive the water pump?

On many engines with a timing belt, but not on all of them. The water pump pumps coolant through the engine and the radiator. According to the ANWB, the pump is driven via a pulley by an auxiliary belt or by the timing belt or chain. Parts manufacturer Dayco writes that many cars with a timing belt also use that belt to drive the water pump. There are also electric coolant pumps, which work independently of the engine speed.

How the water pump is driven What it means when the belt is changed
By the timing belt The pump is exposed as soon as the belt is off. Replacing it at the same time is advised.
By the auxiliary belt (on the outside of the engine) The pump is separate from the timing drive. It does not need to be replaced, unless it leaks or the manufacturer prescribes it.
By the timing chain The pump is replaced if it leaks or if the manufacturer prescribes it. According to the ANWB, you can then expect it to last at least 120,000 km.
Electrically The pump has no belt. It is assessed and replaced separately from the timing drive.

Sources: ANWB (water pump), Dayco and MS Motorservice. We look up how it works on your engine from your registration number.

Why replace the water pump at the same time as the timing belt?

For three reasons: the pump wears at the same rate, the work overlaps and an old pump can damage the new belt. The sources agree on this:

  • Same wear. According to Dayco, the belt, the tensioners and the water pump wear at a similar rate. The ANWB advises replacing the pump as a precaution if it is driven by the timing belt.
  • The work has already been done. To replace the belt, the cover has to come off and the belt has to be removed. The pump is then within easy reach. If the old pump fails later, the ANWB says the belt has to be replaced again as well and you pay for that labour a second time.
  • Coolant is bad for the belt. Dayco writes that coolant from a worn, leaking water pump can attack and destroy a new timing belt.
  • A new belt puts more load on the old pump. Parts manufacturer Gates writes that a worn pump can cope with the tension of the old belt, but that the tension of a new belt puts extra load on the bearing. According to Gates, the old pump is then likely to cause problems after 20,000 to 30,000 km.
  • A seized pump damages the belt. If the pump bearing seizes, Gates says the friction damages the back of the timing belt. In the worst case the belt breaks, possibly causing serious engine damage.

When does the water pump not need replacing?

When the timing belt does not drive it. On an engine where the auxiliary belt drives the pump, or with an electric pump, the pump is separate from the belt change. Replacement is then only needed if the pump leaks, makes noise or if the manufacturer prescribes an interval.

For the wet belt of the 1.0 and 1.2 PureTech, the water pump is not included in our package price. If it needs replacing, we tell you in advance. What is included in that price is explained in timing belt replacement cost.

Not sure whether it is needed on your engine? We look up from your registration number how the pump is driven and what the manufacturer prescribes. If the pump is on the quote, we explain why.

How can you tell the water pump is failing?

The first sign is usually a leak. According to the ANWB, an ageing pump often starts to leak coolant. If coolant gets into the bearing, the bearing runs more and more stiffly and the pump eventually seizes. Gates names noise and leaks as the best-known signs. Look out for these:

  • You have to top up the coolant. If the level in the expansion tank keeps dropping, something is leaking. The ANWB then advises having the cooling system checked, including the water pump.
  • Traces of coolant. A coloured, sticky residue or drips under the front of the engine, on the side of the belt.
  • Noise. Humming, squealing or droning from the area of the timing drive or the auxiliary belt, caused by a worn bearing.
  • The temperature rises. The temperature gauge reads higher than normal or the coolant warning light comes on. The engine is then not getting enough cooling.
Is the red coolant warning light on or is the temperature gauge in the red? Stop as soon as it is safe and switch off the engine. The ANWB warns that the engine can otherwise overheat and suffer serious damage. Do not open the cap of the expansion tank while the engine is hot. What to do next is explained in engine overheating.

How to check the level yourself and choose the right coolant is explained in checking and topping up coolant (in Dutch).

How much does it cost to replace the water pump at the same time?

The part is not expensive. According to the ANWB, the water pump itself costs a few tens of euros up to around € 100 (checked November 2026). The labour depends on how the pump is driven. If the timing belt drives it, most of the work overlaps with the belt change. A new pump also means new coolant, because the system partly drains before the pump is fitted.

For replacing the timing belt, the ANWB gives a range of around € 300 up to € 1,000, depending on make and model (checked November 2026). That is a market indication. With us, we tell you one price in advance based on your registration number, with the pump included if the belt drives it.

How we replace the timing belt and the water pump

We look up the interval for your engine from your registration number and replace the belt with the tensioners and, if needed, the water pump. We tell you one price in advance. This is how we work:

  1. We look up the engine code, the prescribed interval and whether the timing belt drives the water pump.
  2. We fit the belt, the tensioner, the idler pulleys and, if needed, the water pump as the manufacturer prescribes, with the crankshaft and camshaft(s) set as the manufacturer specifies.
  3. We fill the cooling system with the coolant the manufacturer prescribes and bleed it.
  4. We let the engine reach operating temperature and check for leaks.
  5. If we find anything else that needs attention, we tell you first. We only carry out repairs with your approval.

More about how we work is on timing belt replacement in Rotterdam. If only the water pump is leaking, separate from the timing drive, see water pump replacement in Rotterdam.

Frequently asked questions

Does the water pump have to be replaced with every timing belt?

No. Only if the timing belt drives the pump, or if the manufacturer prescribes it. If the pump is driven by the auxiliary belt or is electric, it is separate from the belt change. We look it up for your engine from your registration number.

Can I keep driving with a leaking water pump?

No, only if there is no other option. A leaking pump can drain the cooling system, so the engine overheats. If the pump is driven by the timing belt, the coolant can also attack the belt. Have the pump checked soon and stop at once if the coolant warning light comes on.

How long does a water pump last?

According to the ANWB, with normal use and maintenance you can expect the pump to last at least until the manufacturer’s preventive replacement interval. On an engine with a timing chain, the ANWB says that is at least 120,000 km. A leak or noise is a reason to have it looked at sooner.

Is the water pump included for the wet belt of the PureTech?

No. Our package prices for the wet belt of the 1.0 and 1.2 PureTech do not include the water pump. If it needs replacing, we tell you in advance. The timing kit, gaskets, new oil, the oil filter and cleaning of the oil strainer are included in the price.

Does the coolant need replacing when the water pump is new?

Yes. When the pump is replaced, the cooling system partly drains. We then fill it with the coolant the manufacturer prescribes and bleed the system, so no air is left in the engine.

The water pump has failed but the belt is still fine. What now?

If the timing belt drives the pump, the ANWB says the belt has to be replaced as well when the pump has failed. The belt has to come off anyway and may already have been affected by the leak. If the pump is driven separately, it can be replaced on its own. We tell you the cost in advance.

Why does a water pump fail?

Usually because the seal and the bearing wear. According to the ANWB, an ageing pump often starts to leak, and coolant can get into the bearing, so the bearing runs more stiffly and the pump seizes.

Water pump too or not? Call with your registration number

Call +31 10 479 00 00. We look up how the pump on your engine is driven and tell you one price in advance for the belt, the tensioners and, if needed, the water pump.

You will find us at Boterdiep 11 in Rotterdam-IJsselmonde, close to Stadion Feijenoord (De Kuip). We work by appointment. For a quick question or check you can walk in without an appointment.

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