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Dorman M390420 Brake Master Cylinder New OEM Replacement

(2002-2003, 2005 Audi A4 Quattro Avant; 2002-2006 Audi A4 Quattro Base; 2004, 2006 Audi A4 Quattro Cabriolet + 5 more models)

Part of: Dorman Brake Master Cylinder Replacement

Other options in this family: Dorman M39298 Dorman M19012 Dorman M390139 Dorman M630735 Dorman M390200

Manufacturer

Picture for manufacturer Dorman

Part Number

M390420
10 reviews
Sale Price

$123.31

In Stock (5)

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Usually delivered within 2 days

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Fitment guaranteed

Fitment guaranteed

Product Details

The Dorman M390420 is a 100% new replacement brake master cylinder engineered to restore proper braking function. As the hydraulic heart of the brake system, the master cylinder converts pedal pressure into hydraulic force, actuating the calipers and wheel cylinders at each corner of the vehicle. This direct-fit replacement is built to match the original part's design, dimensions, and performance characteristics.

Key Features:

  • Precise OEM Match – Cylinder housing is constructed to match the casting material of the original part for consistent performance
  • Durable EPDM Rubber Seals – All internal rubber components are made from high-quality EPDM compound, providing excellent resistance to glycol-based brake fluids
  • 100% New Construction – Made entirely from new materials; not remanufactured or rebuilt, ensuring the highest level of quality and safety
  • SAE Compliant – Manufactured to meet rigorous SAE International engineering standards
  • Direct-Fit Replacement – Designed for a straightforward installation with no modification required

Dorman is a leading U.S.-based automotive parts manufacturer with over 100 years of experience delivering reliable aftermarket solutions. The M390420 master cylinder is sold as a single unit and is a trusted choice for professional technicians and DIY installers alike.

Products specifications

Fits

2002-2003, 2005 Audi A4 Quattro Avant; 2002-2006 Audi A4 Quattro Base; 2004, 2006 Audi A4 Quattro Cabriolet; 2002-2004 Audi A6 Quattro Avant/Base; 2002-2005 Audi A4 Base; 2003-2005 Audi A4 Cabriolet; 2002-2004 Audi A6 Base; 1997-1998 Mazda Protege

Feature - Benefit 1

Cylinder housing is constructed from high-quality cast iron or aluminum for long-lasting durability

Feature - Benefit 2

All rubber components are of high-quality EPDM compound for resistance to glycol-based brake fluid

Feature - Benefit 3

Direct replacement for a proper fit

Feature - Benefit 4

Manufactured to strict engineering quality standards, each Brake Master Cylinder meets S.A.E. specifications

Package Contents

Master Cylinder

Reservoir Included

Yes

Master Cylinder Bore Diameter

0.875

Thread Pitch

1.0

Master Cylinder Material

Aluminum

Sensor Included

Yes

Rearward Outlet Size

M10 X 1.0

Mounting Hardware Included

No

Secondary Outlet Thread Diameter

10

Number of Outlets

3

A+shipping was quick, communications were quick

quick and easy

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Great prices and quick shipping! I will be back!!

Fast shipping, good customer service!

The item was what i was looking for and the price was right. Item was very good quality. Would order from Autoplicity again.

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Great prices and fast shipping. It doesn't get any better

Excellent price and received the product the next day.

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