Genuine OEM 0021845501 - Suspension Self-Leveling Unit Filter

Product Overview

This Genuine OEM 0021845501 suspension self-leveling unit filter is engineered for Mercedes-Benz models equipped with hydropneumatic or air suspension systems. The filter maintains the integrity of the self-leveling suspension fluid by removing contaminants and particulates that accumulate during normal operation. This genuine Mercedes-Benz part ensures your suspension system maintains proper pressure regulation and ride height control across a wide range of W116, W123, W210, and W220 chassis platforms from 1978 through 2006.

This filter is a wear item and should be replaced during routine suspension system maintenance or whenever the suspension system is serviced.

Symptoms of a Failing Suspension Self-Leveling Unit Filter

• Suspension system warning lights or messages on the instrument cluster
• Vehicle settling or sagging at one or more corners, especially when parked
• Reduced ride height that does not self-correct after engine start
• Hissing or air escape sounds from suspension components
• Uneven tire wear caused by improper suspension geometry
• Difficulty maintaining level stance during braking or cornering

Cross Reference Numbers

This Genuine OEM 0021845501 suspension filter is equivalent to or replaces the following part numbers: 002-184-55-01, 0021845501.

Vehicle Compatibility

This part fits the popular models below. For Fitment Confidence, please use the vehicle selector tool above to verify exact compatibility for your vehicle.

• Mercedes-Benz 450SEL 6.9 (W116): 1978–1979
• Mercedes-Benz 300TD Turbo Wagon (W123): 1979–1985
• Mercedes-Benz E300 Diesel Sedan (W210): 1996–1999
• Mercedes-Benz E320 Sedan (W210): 1996–2002
• Mercedes-Benz E320 4MATIC Sedan (W210): 1998–2001
• Mercedes-Benz E420 Sedan (W210): 1997
• Mercedes-Benz E430 Sedan (W210): 1998–1999
• Mercedes-Benz CL500 Coupe (W215): 2000–2006
• Mercedes-Benz CL55 AMG Coupe (W215): 2001–2005
• Mercedes-Benz CL600 Coupe (W215): 2001–2006
• Mercedes-Benz CL65 AMG Coupe (W215): 2005–2006
• Mercedes-Benz S430 Sedan (W220): 2000–2006
• Mercedes-Benz S430 4MATIC Sedan (W220): 2003–2005
• Mercedes-Benz S500 Sedan (W220): 2000–2006
• Mercedes-Benz S500 4MATIC Sedan (W220): 2003–2005
• Mercedes-Benz S550 Sedan (W220): 2003–2006
• Mercedes-Benz S550 4MATIC Sedan (W220): 2003–2006
• Mercedes-Benz S55 AMG Sedan (W220): 2001–2006
• Mercedes-Benz S600 Sedan (W220): 2001–2006
• Mercedes-Benz S65 AMG Sedan (W220): 2004–2006

This may also fit other applications. Please use the vehicle selector tool to verify fitment.

Often Replaced Together

For a complete suspension system service, many owners replace the following at the same time:

• Suspension system fluid (hydropneumatic or air suspension fluid as specified for your model)
• Suspension accumulator or spheres (if showing signs of pressure loss)
• Suspension control module or height sensor (if suspension warning lights persist)
• Air or hydraulic lines and hoses (if visible leakage or damage is present)

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Frequently Asked Questions

How do I know if my Mercedes-Benz suspension self-leveling system needs a new filter?

Common indicators include suspension warning lights on the dashboard, loss of ride height that does not self-correct after engine start, or a sagging appearance at one or more corners. You may also hear hissing sounds from the suspension components. If your vehicle is equipped with a self-leveling suspension system and you have not serviced the filter within the last 50,000 miles, inspection is recommended.

What is a suspension self-leveling unit filter and why does it need replacement?

The self-leveling unit filter removes contaminants, water, and particulates from the suspension fluid that powers your Mercedes-Benz's automatic ride height adjustment system. Over time, the filter becomes saturated with debris and loses its ability to protect the suspension components. A clogged filter can lead to reduced system performance, improper ride height, and potential damage to valves and actuators.

Is this filter compatible with both air suspension and hydropneumatic suspension systems?

This Genuine OEM filter is designed for Mercedes-Benz vehicles with hydropneumatic or air suspension systems. The specific fitment depends on your vehicle's model year and suspension architecture. Use the vehicle selector tool to confirm compatibility with your exact vehicle before ordering.

How often should the suspension self-leveling filter be replaced?

Consult your Mercedes-Benz service manual for the recommended maintenance interval specific to your model. General guidance suggests inspection every 40,000 to 60,000 miles, with replacement as needed if contamination is evident. If your suspension system shows warning signs, the filter should be inspected and replaced promptly regardless of mileage.

Can I replace the suspension filter myself, or do I need professional service?

Suspension system work on Mercedes-Benz vehicles, particularly those with hydropneumatic or air systems, requires specialized knowledge and tools to depressurize the system safely and avoid injury. Professional technician service is strongly recommended. Improper handling can result in personal injury or damage to expensive suspension components.

What should I do if suspension warning lights remain after replacing the filter?

If warning lights persist after filter replacement, the issue may involve the suspension control module, height sensors, accumulators, or fluid lines. Scan the vehicle's diagnostic system to identify the specific fault code. A qualified Mercedes-Benz technician can diagnose and address underlying suspension issues beyond filter replacement.

Order Genuine OEM 0021845501 today to restore your Mercedes-Benz suspension system to factory specification. In-stock orders ship same or next business day from our U.S. warehouse, and our fitment team is one call away if you need help confirming the right part for your Mercedes-Benz.

Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.