DIY: Brake Booster MK4 TDI

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)



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)



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



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.



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



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)



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)



14. Now its all out.



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 is instructions on how to bleed the brakes:

http://www.myturbodiesel.com/1000q/a4/brake-clutch-fluid-change.htm

THATS IT!


For EXTRA info go here:

http://forums.vwvortex.com/showthre...ooster-DIY-2003-24V-ABS-and-Stability-control

Excellent! Thanks for the great write-up. Sounds like awkward wrenching below
dash. Take aspirin for back.

it was a bit awkward...just push the steering column all the way up and push the drivers seat all the way back....maybe even take out the seat. only 2 bolts hold the seat in place. (plus the rail covers).

well done!

The job is much faster with the VW tool! I have done 3 here in NH at 45 seconds each.

But you do have to get the tool or borrow one which I did. Thanks to Tremblays last chance Garage.

ive heard 50/50 ...some people say its easy to use..some people say it doesnt work at all...maybe i took the "harder" way but saved myself $$ or hunting someone down that has one...cutting took about a minute.

Just one little correction: the brake bleeding sequence is reversed on the newer (mid 2001 model) models that use the Mk60 ABS controller.

Difference between Mk20 and Mk60 controllers (thanks to MoGolf) - In the Mk20, the round cylinder part of the ABS unit is vertical... In the Mk60, the round cylinder is horizontal... (all this applies only to the MkIV chassis) And the clutch master cylinder should be bled first, in any case...

Good outline !!!

Yuri

ahh yes, i read that too...thanks for adding that

Nice. Thank you for the write up. That's slick, cutting the pushrod to negate having to use pedal-rod release tool. Now I see why you need the release tool (if you don't cut the rod), because you can't get to the back of the pedal to release the pair of rod lock tabs.

Did you simply unbolt the master cylinder from the old booster and bolt it to the new one before installing the new booster?

Ross-Tech simplifies the ABS pump purge procedure. In the Bentley manual, it states to perform the automated sequence that runs over 10 times, or so, using large volumes of brake fluid. It makes sense that all you need to do is run the ABS pump briefly to pull fluid through it. I suppose the two front brake bleeders should be open to allow the brake fluid to pass through easily.

--Nate

the brake booster i bought came with a new master cylinder...better that way i think.

http://www.idparts.com/catalog/product_info.php?products_id=2970

great write-up, nice photos.
We do have one here (using the special tool) in the How Tos stcky

Power Brake Booster Removal:

thats the tutorial i followed..but there was hardly any photos so thats why i re-did it.

I figured here was as good a place as any to ask: What would be the reason for all wheels to be off the ground as stated in VCDS ABS bleed instructions?

Can't figure out why that would be a "must"...

Thanks for the nice writeup ! Pics are very helpful.

is there a way to "bleed" the ABS module without VCDS software? Want to replace this myself, but don't have the software. I am getting ready to sell the car

Outstanding procedure write up!

(can someone confirm for me: If you use a power-bleeder, like a Motiv, you don't need to use the VCDS procedure for the ABS module? )