211-611-905B VW Bus Brake Booster - 1974-1979 Type 2 Transporter

Brake Booster (Vacuum Servo) – 211-611-905B

The 211-611-905B is a critical component for any 1974–1979 Bay Window restoration. Over several decades, the internal rubber diaphragm of the original booster can dry out and crack. When this happens, the "power assist" is lost, making the Bus difficult and dangerous to stop in modern traffic. Replacing the booster restores the smooth, responsive braking these vehicles were known for at the end of their production run.

This unit is designed to work in conjunction with the dual-circuit master cylinder. Because it is located underneath the vehicle, it is finished with a corrosion-resistant coating to protect it from road debris and moisture.

Detailed Vehicle Compatibility

VW Bus (Type 2 / Transporter):

• 1974, 1975, 1976, 1977, 1978, 1979

Product Highlights & Features

• OEM Specification: Manufactured to match the original factory volume and pressure ratios, ensuring your braking system operates exactly as the engineers intended.

• High-Quality Diaphragm: Features a modern elastomer diaphragm that is more resistant to fuel vapors and temperature extremes than the original 1970s rubber.

• Ready for Install: Includes the check valve grommet and mounting hardware interface for a straightforward replacement process.

Technical Specifications

• Part Number: 211-611-905B

• Type: Vacuum Power Assist (Servo)

• Application: Front Braking System

• Compatibility: Late Bay Window models only

Installation & Maintenance Tips

• Check the Check Valve: When replacing the booster, always inspect the Brake Booster Check Valve (803-611-933). A faulty one-way valve will prevent the booster from holding vacuum, leading to inconsistent pedal feel.

• Vacuum Line Integrity: Inspect the plastic vacuum hardline that runs the length of the chassis to the engine. Any cracks or loose rubber connectors will cause a vacuum leak that affects both braking performance and engine tuning.

• Master Cylinder Seal: Ensure the seal between the master cylinder and the booster is airtight. If air leaks into the booster from this interface, the power assist will be diminished.