How to Change A VW Golf Master Cylinder

Own a VW Golf? You can change your own master cylinder in a couple hours. Basic hand tools get the job done. As a bonus these instructions should work on just about any car with a plastic brake reservoir and no ABS.

Difficulty: Moderate

Instructions

Things You'll Need:

• Metric combination wrenches
• Optional But Highly recommended-Line Wrenches
• New Master Cylinder
• Brake Fluid
• Bucket for Hot Water
• Bench Vise Or Equivalent
• A large syringe
• Rags
• Receptacle for old brake fluid
• Plastic tubing for bleeding brakes
• A helpful friend

1. Use a large syringe to empty the master cylinder into a glass jar. Disconnect the wiring to the reservoir cap.

2. 
    
   Here's where to use line wrenches. These fittings can strip easily.

   Remove the master cylinder by loosening all four brake lines and the two nuts attaching the master cylinder to the brake booster. Keep rags handy to catch brake fluid. Mark the brake lines to make sure they go back in their original places.

3. 
    
   Clamp it in the vise like this.

   Remove the plastic fluid reservoir from the master cylinder. It's best to clamp one metal ear of the master cylinder in a vise while you do this. The reservoir just pops off, so rock, twist and pry it firmly but carefully away from the master cylinder until it comes free.

4. 
    
   Use plenty of hot water to chase out dirt.

   Fill a bucket with ONLY hot water. Detergent soap may or may not harm brake components, so play it safe. Dunk the plastic reservoir in the water and swish it around to clean it out.

5. 
    
   Compressed air is best, but not absolutely necessary

   Blow the reservoir dry with compressed air. In a pinch, air dry it, or shake it dry.

6. Clamp the new master cylinder into the vice. Remove any plugs or caps plugging the various holes.

7. Reinstall the clean master cylinder reservoir. Push it back down into the rubber grommeted holes in the master cylinder. You'll need to lubricate things with some fresh brake fluid, and wiggle and push down hard. Keep at it, and it should eventually pop right back into place.

8. 
    

   Read the instructions that came with your master cylinder, and then hook up the master cylinder bleeding kit. Take care that all the plastic fittings are tight. Bleed the master cylinder. When finished, put the strainer back in the master cylinder, put the cap on the reservoir, and plug all the orifices in the master cylinder.

9. Install the master cylinder by reversing Step 2. Take care that brake line fittings do not thread crosswise. Factory torque for the brake master-to-brake-booster nuts is only 15-20 ft lbs, be careful not to over tighten them.

10. Bleed the brakes. Once they are bled, start the car and check for leaks by pumping the brake pedal and looking around connections.

11. Drive into the sunset. Enjoy your firm new brake pedal.

Tips & Warnings

• Brake fluid will DESTROY automotive paint. Be sure to keep it off any painted surfaces.