Estimates last updated October 16, 2025

1994 Mercedes-Benz S420 Windshield Washer Pump Replacement Cost

The average cost for a 1994 Mercedes-Benz S420 Windshield Washer Pump Replacement is between $283 and $317*.

Labor costs are estimated between $73 and $107 while parts are typically priced around $210.

Windshield Washer Pump Replacement

What is a windshield washer pump?

Mounted at the bottom of the windshield washer fluid reservoir is a small pump that sends washer fluid to the windshield and, in some vehicles, the headlights or rear window.

How does the windshield washer pump work?

If you press your window washer, and you hear a buzz or hum, that is the windshield washer fluid pump. The pump is activated by the button on the steering wheel, and in some models, this is done indirectly through a signal from the vehicle's computer.

What are the symptoms related to a bad windshield washer pump?

When the windshield washer pump fails to activate the washer nozzles, and the normal buzzing sound is not heard, the windshield washer fluid pump or the electrical circuit is faulty. Also, these pumps crack and leak occasionally, and if water is accumulating on the bottom of the windshield washer fluid pump, the pump or reservoir must be replaced.

Can I drive with a windshield washer pump problem?

Driving without windshield cleaning components is not typically considered unsafe, but there will be no system to properly clean your field of vision if the need arises. If the windshield cleaning system is heavily relied upon in your location, consider repairing the system sooner than later. Also, this system works together to clean and protect the windshield, when one component fails, the risk of damage to the windshield is elevated. Lack of lubrication, incorrect windshield wiper angle, and worn windshield wiper blades are all causes of streaking, grooving, and scratching the path of the windshield wipers into the windshield.

How often do windshield washer pumps need to be replaced?

Mercedes-Benz Windshield Washer Pump Replacement Cost Estimates

The average cost for a Windshield Washer Pump Replacement is between $283 and $317 but can vary from car to car.

Mercedes-Benz S420 Windshield Washer Pump Replacement Cost by Year

The average cost for a Mercedes-Benz S420 Windshield Washer Pump Replacement is between $283 and $317 but can vary from car to car.

1999 Mercedes-Benz S420

$104-$146

1998 Mercedes-Benz S420

$104-$146

1997 Mercedes-Benz S420

$104-$146

1996 Mercedes-Benz S420

$283-$317

1995 Mercedes-Benz S420

$283-$317

1994 Mercedes-Benz S420

$283-$317

*This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

For a more accurate estimate based on your location, use our Fair Price Estimator.

Windshield Washer Pump Replacement

Jump to:Cost estimates by vehicle Cost estimates by year

What is a windshield washer pump?

Mounted at the bottom of the windshield washer fluid reservoir is a small pump that sends washer fluid to the windshield and, in some vehicles, the headlights or rear window.

How does the windshield washer pump work?

What are the symptoms related to a bad windshield washer pump?

Can I drive with a windshield washer pump problem?

How often do windshield washer pumps need to be replaced?

Mercedes-Benz Windshield Washer Pump Replacement Cost Estimates

The average cost for a Windshield Washer Pump Replacement is between $283 and $317 but can vary from car to car.

Windshield washer fluid pumps and reservoirs fail about as often as you think about their existence. When failure does occur, it is usually from the engine simply wearing out, or the pump being run without liquid in the windshield washer fluid reservoir. To keep the pump in good running condition, keeping the coolant reservoir full of fluid a big help.

How are windshield washer pump issues diagnosed?

Windshield washer fluid pumps are diagnosed by a guided process of elimination, from most likely, to least likely. The fuses are checked first, then the power at the windshield washer switch, then power coming from the switch, to the washer fluid pump motor. If there is electrical power going to the windshield washer fluid switch, but the switch will not send power to the windshield washer pump motor, the switch or wiring must be replaced. If the switch sends power, but the windshield washer pump will not run, power at the windshield washer pump would be checked. If electrical power reached the pump motor, but the motor did not run, it would be bench-tested, and confirmed failed.

How is a windshield washer pump replaced?

To replace the windshield washer pump motor, the reservoir must be accessed, as it is normally installed in, on, or near the windshield washer fluid reservoir. The fluid reservoir can be installed anywhere on a vehicle. They are commonly seen under the hood, behind the fender wells, behind the bumper yet in front of the core support, or, of all places, in the trunk. Once it is located and accessed, the old pump will unclip, or unscrew, and the new will go on in reverse order. Once the washer fluid pump is tested, the vehicle can be reconstructed.

RepairPal Recommendations for windshield washer pump issues

Some windshield washer replacement pumps do not come with sealing washers provided, and the technician may re-use or replace the sealing washers. We recommend replacing the sealing washers if the manufacturer specifies this as part of the procedure. If there is no guidance, changing the seal is the best choice

What to look out for when dealing with windshield washer pump issues

In most cases, a technician will charge a diagnostics fee for testing the system, and determining the windshield washer fluid pump is faulty. This protects the customer from needlessly replacing a properly functioning component.

Can I replace the windshield washer pump myself?

Testing and replacing the windshield washer pump is simple on most vehicles, and access is generally small but sufficient. Ensure that the motor is tested from an external power source to test functionality, even if diagnosed faulty. If the pump is too difficult, or requires deconstruction to access, consider contacting a certified repair facility.