Mercedes ML W166 ABS Pump Brake Hydraulic Module Pump Unit A1669013400

Mercedes ML W166 ABS Pump Brake Hydraulic Module Pump Unit is an original component from the ABS and ESP System group, designed for Mercedes vehicles. It is a complete base for restoring the proper operation of the hydraulics and pressure control in the braking system, particularly important for repairs following a failure or when upgrading the ABS system.

Specifications and technical data

• SKU: A1669013400
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1669013400
• Substitutable numbers: A1669013400, A 166 901 34 00
• Category: ABS & Stability Hydraulic Units

Purpose and function in the vehicle

The ABS brake pump in the ML W166 model is responsible for generating and precisely metering pressure in the brake circuits, working in conjunction with the electronic control of the ABS and electronic stability program. A correctly selected component from this group helps maintain vehicle stability during emergency braking, reduces wheel slip, and ensures predictable vehicle behavior on slippery surfaces.

By using an original component from the Mercedes family, compatibility with the factory operating characteristics of the system is maintained, which translates into consistent performance of safety systems such as ABS and ESP.

Benefits of using an original ABS brake pump

Using a factory-original solution in the braking system ensures:

• Full integration with vehicle electronics – proper cooperation with wheel speed sensors and the control module.
• Stable hydraulic operating parameters – predictable pressure in the brake circuits under various road conditions.
• Reduced risk of ABS and ESP system errors – lower chance of fault messages appearing due to incorrect part selection.
• Possibility of professional diagnostics – compatibility with factory service procedures and diagnostic testers.

Product characteristics and selection by part numbers

The presented ABS brake pump belongs to the group of pressure control elements in the ABS and ESP System and was designed specifically for Mercedes vehicles. Selection is based on the OEM part number and interchangeable numbers, which allows for precise matching of the component to a specific equipment version and model year, minimizing the risk of incompatibility.

In case of any doubts regarding fitment, it is recommended to verify compatibility using catalog numbers or to physically compare the old and new units, paying attention to the connector type, layout of the ports, and the mounting method in the vehicle.

Condition and service application

The offered item is in used condition, making it an attractive solution for economical repairs where the priority is to maintain the original system design at reasonable service costs. This type of component is suitable both for replacement after hydraulic or control failure and for comprehensive brake system restoration following mechanical damage.

Before installation, a standard service procedure is recommended: checking line tightness, bleeding the system, and verifying the correct operation of the ABS and ESP system using a diagnostic tester.

Brake system upgrade expansion

If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other elements from the same group, such as control modules, wheel speed sensors, or pressure lines, check out the available parts in the Mercedes ABS and ESP System category.

Technical and diagnostic support

When working on safety-critical systems, it is worth understanding how the braking system interacts with other vehicle systems. To learn more about the dependencies between brake hydraulics, electronics, and vehicle handling, read the article on our blog: Steering system and power steering – how it works and what fails?. This will provide a comprehensive overview of vehicle behavior during braking, maneuvering, and driving in difficult conditions.