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Discussion Starter · #1 ·
Hi all,

I've seen the numerous threads about the brakes being a pain to bleed and that the ABS pump requires pressure bleeding and etc..

2002 Mk4 GTI Anniversary

Originally all the calipers where taken of because the paint was flaking of real bad.

Now that they've gone back on the brakes haven't been right ever since!

So far the hoses have been replaced and the master cylinder.. I managed to borrow a Brake bleeding machine of a mate which does the whole process automatically. The only improvement i've had is that the car is able to stop upto 30mph.. after that your in trouble, because there simply is no pressure..

We've tried the method with the Launch X431 diagnostic which has the option to bleed the ABS pump, again.. Nothing!

Then tried the method again with Vagcom and still.. Nothing!

Can anyone recommend if the next step is to get a replacement SERVO and see if this may do the trick?

or if can recommend a VW/Audi Specialist who will not faff about and get straight to it..

I'm located in East london..

Thanks fella's..
 

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NooNoo
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Have you done the servo checks?

I presume it does actually assist and give you that 'squelch' sound when applying the brakes?

Also after turning the car off the first few brake pedal pushes should be soft, then the pedal should go hard.

I have replaced my servo due to the diaphragm leaking, a constant hiss that can be heard with the brake pedal applied.

You could disconnect the vac feed line briefly from the servo body and do a test drive on a private drive/area. Be aware you should need alot more force on the pedal to stop. If the pedal feels the same with the vac line disconnected then it could indicate a problem with the servo. Do not drive it on the road disconnected.

Do you really have to apply the brakes hard to get any stopping force?

Does the pedal just go to the floor too easily?

[:)]

Edit: You will need to bung the open end of the servo vac line. It will need more than just tape. Otherwise your idle and air/fuel mix will be upset badly (as air would be continously sucked into the inlet manifold).
 

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Discussion Starter · #3 ·
The pedal does require more than normal force in order to get it to stop.

The pedal also does drop to the floor very easily.

Will do the servo checks again once more, the funny thing is the servo seems to do it's job when the car is turned off e.g. first few pushes are soft then it becomes hard.
 

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NooNoo
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All bleed nipples are facing upwards? (daft question I know but I read on here that someone managed to get the calipers upside down!!! How on earth?). Sounds like you know what you're doing tbh.

Do all bleed points expell fluid and no bubbles?

When you brake is it only the very bottom of the travel that works?

Sounds like trapped air to me but I think you have exhausted that one!

I've bled my brakes many times, when I've painted front and rear calipers etc.

[:cool:]
 

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NooNoo
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Sounds like the OP has used a pressure bleeder... so no pedal action required.

[:)]
 

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Discussion Starter · #7 ·
Tried both methods, tightening the the nipples up when excessive fluid comes up straight away, when manualling pumping the pedal

Also..

Like mentioned earlier, have used the self bleeding machine, which does everything itself.

The brakes only bite like 15% when the pedal is right on the end..

[:(]
 

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NooNoo
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How good is the machine you're using?

After upgrading my rear calipers to 256mm x 22mm vented last year it took me 3 days to eek out evey last bubble of air from the calipers.

I use a Gunsons Ezibleed. I would still say the brakes aren't as sensitive as they are 'out the factory'.

[:)]

My rear caliper DIY: -

http://uk-mkivs.net/forums/p/382241/2607101.aspx#2607101
 

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Have you bled the master cylinder nipples?
 

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Discussion Starter · #10 ·
Every bleeding nipple from master cylinder right the way down to each caliper has been thoroughly bled manually..

I can't remember the exact name of the Machine, but it looked very similar to a Henry hoover, lol!
 

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I have exactly the same problem on my S plate GTi. Rear O/S banjo leaked until the brakes failed. Replaced the brake line, filled the reservoir and bled the brakes time and time again. If anyone knows a specialist in Brighton area please point me in the right direction!
 

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If the pedal does drop to the floor very easily that's mean the system is not bleed corectly. If the pedal is hard and U still have problems to stop the car that's mean servo is gone or (on some models) Secondary Air pump.

First - to bleed all the system - start from the rear to the front. Then MBC and as the last the ABS pump with VAG. But to do it (if I good remember) U need to lift the car up (wheels cannot touch the ground).

But of course I can be wrong.
 
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