brake vacuum booster replacement on mk4 vw

Apr 26, 2014
brake vacuum booster replacement on mk4 vw
  • How to replace the brake booster on VW mk4- (98-2005/6)

    This article shows how to DIY remove and replace the vacuum brake booster on a mk4 VW TDI (Golf, NB, Jetta)

    difficulty: 2/5

    Introduction

    The brake booster provides power assist for the brakes. It uses vacuum from the vacuum pump at the end of the cylinder head. A rubber diagraphm and spring is inside the booster. If the vacuum pump or brake booster fail, you could lose power assist for the brakes. Any loss of vacuum can also cause malfunctions in the turbo control and exhaust gas recirculation system since they're powered by vacuum too. Symptoms would include a constant hissing noise or when pressing on the brake pedal, loss of power braking, or loss of vacuum.

    The original writeup is by Combine17, for support on this article please post in this forum thread.

    Parts
    brake booster (check the PN for your application): VW# 1j1 614 106 j

    Procedure
    I replaced my brake booster today, so I'm going to create a short DIY with pictures since there isn't any of these out there

    1. Take out all the covers that are underneath the steering wheel. You'll need to get to the brake pedal from here.

    2. Unplug and disconnect the GREEN Brake switch from the brake pedal bracket (yellow arrow)

    3. Unbolt the bracket that joins the brake pedal and the clutch (2 red arrows)

    [​IMG]

    4. Take a dremmel and CUT the brake booster ROD...this makes the whole job easier...try and cut it as closest to the firewall as possible.

    5. Now unbolt the nut that hold the brake pedal in place. You should be able to swing the brake pedal back and forth now since the brake booster rod is cut. (red arrow)

    [​IMG]

    6. Now Unbolt the 4 Nuts that hold the whole brake booster in place. (4 red arrows)

    [​IMG]

    7. You can now take the brake pedal out of the car and look at the back of it. Here is a picture of the back.

    [​IMG]

    8. Push in a screw driver into each tab while pulling out the rod. It will then pop out. (2 red arrows)

    [​IMG]

    9. Once you have the rod out you can now put the brake pedal back into the car. Bolt it back up using the one bolt and let it just hang there for now.

    10. You are now done inside the cabin...move into the ENGINE BAY.

    11. Using a wrench undo the ABS lines that are going from the ABS module to the MASTER CYLINDER. (2 red arrows)
    Then unplug the rubber hose that is going from the clutch pedal to the brake fluid reservoir. (1 red arrow)

    [​IMG]

    12. Unbolt the THREE 10mm bolts that hold down the ABS module. You will need to move the module a little bit to the side so that the brake booster can slide out.

    13. Using a breaker bar or a long screw driver pull back the ABS module BRACKET at the same time as you're pulling the brake booster out. This will give you enough clearance for the booster to slide out to the side. (red arrow)

    [​IMG]

    14. Now its all out.

    [​IMG]

    NOW FOR THE INSTALLATION:

    15. Slide the new brake booster in the same way you got it out. Use the breaker bar again for more clearance.

    16. Once the brake booster is all lined up in the engine bay go inside the cabin and bolt up the 4 brake booster nuts into the brake booster. DONT tighten them yet. You still need to pop the brake booster ROD into the brake pedal.

    17. Once you have the 4 nuts little bit snug, line up the brake booster rod with the back of the brake pedal and give it a good push. The rod will pop back into place.

    18. You can now tighten all 4 brake booster nuts.

    19. Put the back the clutch/brake pedal bracket....and then the brake pedal GREEN switch. Then put all your panels back on. You are now done inside the cabin.

    20. Now that your brake booster is in and installed, you can put the ABS module back into place. Bolt up the THREE 10mm bolts.

    21. Same goes with the ABS lines that run into the master cylinder. After that, connect your clutch rubber hose to the brake reservoir.

    22. Put back your air box and you are done.

    NOW YOU NEED TO BLEED THE SYSTEM.

    23. Go into VAGOM and run your ABS module (about 2 times). This will push the air bubbles into the brake lines.
    Here is the instructions:

    http://www.ross-tech.com/vag-com/cars/absbleeding.html

    24. Now you can proceed to bleeding the brakes. Start with REAR RIGHT then REAR LEFT then FRONT RIGHT then FRONT LEFT. Lastly bleed your clutch slave cylinder as well.
    Here are instructions on how to bleed the brakes: http://www.myturbodiesel.com/wiki/brake-fluid-and-clutch-bleeding-and-flush-mk3-and-mk4-vw-and-audi/