1. Check the brake fluid level. Make sure the brake fluid reservoir is full. If it's low, add brake fluid and try pumping the brakes again.
2. Make sure the brake lines are clear. Disconnect the brake lines from the master cylinder and check to make sure there are no obstructions. To free up an obstructed line you can blow compressed air through the open line.
3. Check the master cylinder. If the brake fluid level is full and the brake lines are clear, the problem could be with the master cylinder. Remove it and inspect it for any damage or leaks.
4. Check the proportioning valve. The proportioning valve regulates the amount of brake fluid that is sent to the front and rear brakes. If it is malfunctioning, it could cause the front brakes to not get enough fluid.
5. Bleed the brakes. If you've done all of the above and you still can't get the brakes to pump up, you may need to bleed the brakes. This process involves removing the air bubbles from the brake fluid lines and replacing them with brake fluid.
Here are detailed steps on how to bleed the brakes on your 1971 VW Bug:
1. Gather the following materials:
- A brake bleeding kit
- A clean, clear container
- Brake fluid
- A wrench
2. Start by parking your car on a level surface.
3. Turn off the engine and allow the car to cool down.
4. Open the hood of your car.
5. Locate the brake fluid reservoir. It is usually located near the master cylinder.
6. Remove the cap from the brake fluid reservoir.
7. Add brake fluid to the reservoir, if necessary.
8. Attach the brake bleeding kit to the bleeder screw on the first wheel cylinder/ brake caliper. Be mindful there is a bleeder screw on each side of the brakes you are working on. (i.e. 2 bleeders for front wheel cylinders, and 2 bleeders on front brake calipers)
9. Place the end of the brake bleeding kit into the clean, clear container.
10. Have a helper slowly depress the brake pedal down.
11. While the brake pedal is depressed, open the bleeder screw slightly. Air bubbles should start to come out of the bleeder screw and into the container.
12. Keep the brake pedal depressed until the air bubbles stop coming out of the bleeder screw.
13. Close the bleeder screw.
14. Repeat steps 8-13 for the remaining brake wheel cylinders/ calipers.
15. Top up brake fluid in reservoir as needed.
16. Test the brakes by pumping the brake pedal. The pedal should feel firm and should not go all the way to the floor.
16. If the brakes still do not work properly, you may need to take your car to a mechanic for further diagnosis.
