I find that I need to step on my brake paddle a lot harder than I have to do on other cars to get the same speed reduction. Is this by Audi design or there is something wrong in the system? Thanks for any advice. Mine is a 99 A6 2.8L.

Brakes on any audi's are second to none so it should put your face into the steering wheel if you pushed the pedal down hard. Have someone pressure bleed the system and try it again.

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00 A4 1.8T

01 S4 SOLD!!!

Thanks for the input. But if you could educate me a little bit. What is the purpuse of pressure bleeding the system?

Pressure bleeding is probably the best way to bleed the brake/clutch hydraulic system. What it does is put compressed air about 1 bar (14.7 psi) into the brake fluid resivior while filling the resivior at the same time. Then you just crack open the bleeders at all four wheels in the specified sequence: left front, right front, left rear, right rear.
The dealer has the factory tool for this which is a very effective machine, here is the machine.
The dealer is gonna be the best place to get it done right, take it there and say you just want a complete brake fluid flush, its gonna be more expensive but if you want it done right, this is the way to go.

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00 A4 1.8T

01 S4 SOLD!!!

i had the same issue with my 2.8, i have replaced, what is refered to as the suction pump and it has sorted the problem.

if you look at www.audiworld.com/tech/eng.html

scroll down in the A4 area you will find a suction pump replacement article which will guide you through.

i have done this the part was about £16.

matt

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I did replace the suction pumpbut it didn't help. I did it for another issue though. What does the pump do in this case anyways?

It doesn't do much for the braking system as much as it does for the crankcase ventilation system. If the pedal is really that hard to depress and it looks like vaccum line to the brake booster is good you probably have a bad brake booster.

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00 A4 1.8T

01 S4 SOLD!!!

the suction pump has a one way valve inside the unit, mine was not working and allowing free travel of air in both directions.

the large bore part of this unit goes between the inlet manifold and the vacuum side of the brake servo and provides the vaccuum for the unit.

the small bore side pipe links to the breather system.

you should be able to suck freely in one direction only on the large bore unions, however the one way valve does not affect the small bore breather system union.

depending on how long ago you changed it, it may be worth checking the operation of this unit, before cracking open the brake system.

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Can anyone give details on checking brake servo on my 1998 2.8 v6.
Currently extra effort required on brake pedal required ,to get good braking.
There is instant pedal resistance, so not related to any brake bleeding problems.
Boba6.

I have soft brakes too, I was looking into stainless steel brake lines ($112 a set). My brotheronly replaced his front rotors and that help his A6 a lot. I would say replace the rotors and get the stainless steel lines.

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Just my 2 cents, keep the change....and your smart remarks
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