Baywindow Bus Master Cylinder - 1971-79 With Servo Brakes

Replacement reproduction brake master cylinder for VW Baywindow Buses from 1971 to 1979 fitted with servo-assisted brakes. This dual circuit master cylinder is designed to restore safe, reliable braking performance on late Baywindow models.

The master cylinder is the heart of the hydraulic braking system, converting brake pedal movement into hydraulic pressure which operates the wheel cylinders or brake calipers. Over time internal seals can wear or fail, causing fluid leaks, sinking pedals, poor braking performance, or brake fluid bypass issues. Replacing a worn master cylinder is essential for maintaining safe braking operation.

This reproduction unit is manufactured primarily for left hand drive models, however it can also be fitted to right hand drive buses by modifying and rerouting the brake pipes to suit the port layout.

Important Fitting Notes

• Brake light switch not included
• Compatible brake switches:
  • 2 terminal switch: 113945515H
  • 3 terminal switch: 113945515G
• Some brake pipes may require rerouting due to different port positioning
• Brake switches must sit below the master cylinder centreline to prevent trapped air during bleeding
• Brake pedal pushrod end play must be adjusted to factory specification of 1mm
• Pushrod length may require trimming on some applications

Specifications

• Quality: Reproduction
• System: Dual circuit servo brake system
• Outlets: 4
• Reservoir centres: 85mm
• Application: Servo-assisted braking systems

Recommended Additional Parts

• Brake fluid reservoir seals
• Brake fluid reservoir hoses
• Brake light switches
• Brake pipe unions or replacement brake lines
• Brake fluid
• Servo vacuum hose and seals

To Fit

Aircooled VW

• VW Baywindow Bus – 1971–1979
  • Servo brake models