BMW 3 Series E90 E91 E92 335d M57N2 Steering Expansion Hose Pipe Line 6772804

BMW 3 Series E90 E91 E92 335d M57N2 Steering Expansion Hose Pipe Line is an original hydraulic system component, designed specifically for the M57N2 engine version. Thanks to its factory geometry and correct pipe diameter, it ensures stable operating pressure and predictable steering system performance under demanding operating conditions.

Specifications and technical data

• SKU: rhd-6772804
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6772804
• Substitutable numbers: 32416772804, 6772804, 32414047316, 4047316, 32414045582, 4045582, EM
• Category: Other Steering & Suspension Parts

Purpose and function in the steering system

This steering expansion hose is responsible for the controlled flow of fluid between hydraulic components, which limits pressure spikes and reduces vibrations transmitted to the steering rack. In BMW 3 Series E90, E91, and E92 models with the 335d M57N2 unit, it is crucial for:

• maintaining smooth, predictable steering assistance at various engine speeds,
• reducing noise and pulsation in the system,
• protecting the power steering pump from pressure overloads.

Due to its fitment for the specific engine-chassis configuration, the hose maintains the correct routing in the engine bay, which minimizes the risk of abrasion and leaks.

Construction and fitment for BMW 3 Series 335d M57N2

Original BMW construction means compatibility with factory mounting points and the correct length and shape of the hose. The connectors are prepared for use with the stock power steering pump and other system components, which facilitates installation without modifications.

The hose has been designed to operate at high temperatures and under significant operating pressure, typical for the powerful 335d diesel engine. Properly selected materials, as well as flexible and rigid sections, allow for limiting the transmission of vibrations to the chassis while maintaining system stability.

Benefits of using the original hose

Using the expansion hose dedicated to the BMW 3 Series 335d M57N2 brings a number of practical service and operational benefits:

• Factory fitment – no need for modifications, drilling, or custom mounts.
• Consistency with system parameters – maintaining the pressure and fluid flow designed by the manufacturer.
• Reduced risk of leaks – the correct type of connectors and seals intended for this model.
• Stable vehicle handling – uniform steering assistance across the entire RPM range.

This used component allows for an economical repair of the system while maintaining the original manufacturer's specifications, which is particularly important in the case of high-performance units such as the 335d.

Professional installation and diagnostics

When replacing the power steering expansion hose, it is recommended to:

• thoroughly bleed the system after installation,
• check the condition of other hoses and connections,
• verify the operation of the power steering pump under load,
• check for any potential leaks after the first few kilometers of driving.

This approach allows for restoring the proper operation of the steering system and minimizing the risk of further service interventions.

If you are planning a comprehensive repair or upgrade of the steering system area in your BMW and need other components from the same group, such as hydraulic hoses, fluid reservoirs, or additional mounts, check the available parts in the Other BMW category.

For drivers interested in comparing the characteristics of powerful premium model versions with other variants, including differences in drivetrains, braking systems, and suspension, the article on our blog may be helpful: Audi RS vs other models – what is hidden under the hood and chassis?.

If you want to better understand how using used components – such as power steering hoses – affects service costs and the environment, check out our guide: Eco-driving: discover the benefits of used car parts, where you will find practical tips on conscious vehicle operation.