Dorman 47424 Power Brake Booster Check Valve

Power Brake Booster Check Valve for Audi and Volkswagen

Dorman 47424 is a power brake booster check valve built to match the fit and function of the original valve on specified vehicles. It is made from plastic with a black finish and a straight outlet, giving you a direct replacement for brake booster vacuum control on select Audi and Volkswagen applications.

Use this Dorman 47424 check valve when servicing a brake booster vacuum line on vehicles such as the Audi A4 Quattro, Audi A6, and Volkswagen Passat with two-port configurations. The part number 47424 is also a practical OE-style replacement for drivers looking for a straightforward brake system repair.

Key Features

• OE-style power brake booster check valve for brake vacuum systems
• Plastic construction with black color/finish
• Straight fitting outlet for a clean hose connection
• One outlet design
• Valve opening size: 0.2 in
• Grommet end outside diameter: 0.332 in
• Hose end outside diameter: 0.331 in

Detailed Description

This Dorman brake booster check valve is engineered to match the original valve’s fit and function on specified Audi and Volkswagen vehicles. It helps maintain proper one-way vacuum flow to the power brake booster, which is critical for consistent brake pedal assist. This part cross-references URO 058905291K for the same application. If you are replacing a worn or leaking brake booster valve on an Audi A4 Quattro, Audi A6, or Volkswagen Passat, 47424 provides a direct-fit service part for two-port systems.

What It Helps Fix

• Hard brake pedal feel caused by vacuum loss
• Brake booster vacuum leakage
• Reduced brake assist after engine shutdown
• Check valve sticking or failure
• Vacuum hose connection issues at the booster line

Installation Notes and Tips

• Verify the vehicle uses a two-port configuration before ordering.
• Inspect the brake booster hose and grommet for wear before installation.
• Confirm the hose and grommet diameters match the existing setup.
• Install in the correct flow direction so vacuum is retained in the booster.
• After installation, check brake pedal feel and inspect for vacuum leaks.

Quality Assurance

Dorman designs this replacement valve to match original equipment fit and function for specified applications. The part number 47424 is built for durable, reliable performance in brake vacuum service.