Mercedes W639 Air Suspension Bag Air Bellow Left N/S Hose A6393280101

Mercedes W639 Air Suspension Bag Air Bellow Left N/S Hose is a component from the Automatic level control group, designed for an axle equipped with pneumatic height maintenance. It enables stable body support, ensuring predictable vehicle behavior under varying loads and improving ride comfort. This solution is particularly valued in commercial and passenger vehicles, where safe handling and even weight distribution are essential.

Specifications and technical data

• SKU: A6393280101-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6393280101
• Substitutable numbers: A6393280101, A 639 328 01 01
• Location on the vehicle: Left
• Category: Self-Levelling Suspension Parts

Purpose and function in the suspension system

The air suspension bag in Mercedes W639 series models is responsible for maintaining the set body height relative to the axle, working in conjunction with the Automatic level control system. In practice, this means compensating for suspension deflection during loading, trailer towing, or dynamic driving, which translates into stable handling and better vehicle control.

The presented set is designed for the left side, which is important when selecting parts for a specific suspension configuration. Proper matching of the mounting side reduces the risk of improper system operation, uneven leveling, and accelerated wear of other components.

Construction and benefits of using an air suspension bag

The air suspension bag in this solution acts as a resilient load-bearing element that replaces or supports a classic steel spring. Thanks to the ability to regulate pressure in the system, it allows for:

• maintaining a constant body height under various loads,
• reducing body roll during maneuvers,
• improving ride comfort on uneven surfaces,
• more even distribution of loads on suspension components.

In Mercedes W639 vehicles, this solution is particularly useful in transport and family applications, where the weight of the cargo or the number of passengers often changes. Using a properly selected air suspension bag helps maintain predictable vehicle behavior and reduce tire wear.

Mounting and operational characteristics

The offered element is intended for installation on the left side of the vehicle, which should be taken into account when planning service work. Replacing an air suspension bag requires following safety procedures related to working on a raised vehicle and the pressure system, therefore installation in a specialized workshop is recommended.

As a part from the Automatic level control group, the bag works with other system components – height sensors, pneumatic lines, and controls. A properly selected and installed element allows for restoring the correct operation of the leveling system, eliminating symptoms such as one side of the vehicle sagging, uneven ground clearance, or excessive body sway.

Product condition and practical application

The air suspension bag offered in this set is a used component, which makes it an attractive cost-effective alternative for repairs of vehicles used intensively or with higher mileage. This type of solution is often chosen by workshops specializing in Mercedes service, as well as by conscious users looking for parts with a favorable price-to-functionality ratio.

Before installation, standard leak verification and inspection of cooperating pneumatic system components are recommended to ensure consistent operation of the entire system. Replacing the bag on one side is often combined with checking the condition on the opposite side, which helps reduce the risk of further service downtime.

System expansion and selection of related elements

If you are planning a comprehensive repair or upgrade of the suspension zone with leveling function in your Mercedes and need other elements from the same group, such as additional air suspension bags, supply lines, or components cooperating with the leveling system, check the available parts in the Automatic level control Mercedes category.

For users who want to deepen their knowledge about the selection and operation of drivetrain components, a guide describing typical faults and rules for purchasing used gearboxes may be useful – you will find it in the article Gearbox: manual, automatic or DSG – typical faults and a guide to buying a used gearbox.

If you want to better plan your purchases of used parts, including air suspension elements, it is worth reading a practical guide to safely choosing components online, available in the material Safe purchase of used car parts online – a step-by-step guide.