Mercedes Vito Viano W639 Clutch Master Cylinder A6392900012

The Mercedes Vito Viano W639 Clutch Master Cylinder is an original, used clutch master cylinder designed for the drivetrain of Mercedes Vito and Viano models of the W639 generation. This component is responsible for precisely transferring force from the clutch pedal to the hydraulic system, ensuring stable clutch operation and predictable vehicle behavior. Thanks to its genuine Mercedes origin, you receive a part with proven structural fit for the specific W639 platform.

Specifications and technical data

• SKU: A6392900112
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6392900112
• Substitutable numbers: A6392900112, A 639 290 01 12, A6392900012, A 639 290 00 12, KD
• Category: Additional Clutch Parts

Purpose and Function in the Clutch System

The clutch master cylinder in the Mercedes Vito and Viano W639 plays a crucial role in the clutch control hydraulics. It is responsible for:

• generating appropriate pressure in the hydraulic system when the pedal is pressed,
• precise control of clutch disengagement, which affects the smoothness of gear changes,
• maintaining a repeatable engagement point of the clutch pedal.

A well-chosen master cylinder reduces the risk of problems such as pedal sinking, pressure loss, or difficulty engaging gears, which directly impacts driving comfort and safety.

Original Origin and Fit for Mercedes Vito / Viano W639

The presented clutch master cylinder for Mercedes Vito and Viano W639 comes from the Mercedes parts line, meaning it retains factory assembly and functional parameters. The original design ensures:

• compatibility with factory mounting points on the bulkhead,
• correct positioning relative to the clutch pedal and hydraulic lines,
• compatibility with the standard clutch system components used on the W639 platform.

This allows for installation similar to factory servicing, without the need for modifications or adjustments of replacement parts of uncertain origin.

Used Condition and Benefits of Choosing Dismantled Parts

The item is offered in a used condition, which represents a reasonable compromise between cost and functionality, especially for vehicles used intensively or in fleets. Choosing a used clutch master cylinder can be beneficial when:

• you are looking for an economical solution while maintaining original Mercedes specifications,
• the vehicle has significant mileage and investing in a brand-new part is less economically justified,
• quick restoration of clutch system functionality is important while maintaining correct fit.

To better assess when purchasing a used drivetrain component is worthwhile, consult the guide: Used Gearbox – When is it Worthwhile and What You Need to Know, which discusses practical aspects of selecting parts from the aftermarket.

Installation and Operational Aspects

The clutch master cylinder in the Mercedes Vito / Viano W639 is integrated with the pedal system and clutch hydraulics. Therefore, during its replacement, it is important to adhere to service procedures such as:

• proper bleeding of the hydraulic system after installation,
• checking the tightness of lines and connections,
• verifying the pedal travel and engagement point after work is completed.

A correctly selected and installed master cylinder reduces the risk of accelerated wear of other clutch system components and improves the comfort of gearbox operation, especially in urban conditions and during frequent starts.

Offer Supplement and Related Parts

If you are modernizing or servicing the complete clutch control system in your Mercedes Vito or Viano W639 and also need other hydraulic or accessory components, check the available parts in the category Other Mercedes Clutch Parts.