Caliper problem 100 turbo

[saladdodger]

Replaced master cylinder like for like, checked before replacing and was identical. Had this issue with the old master cylinder that's why i bought a new one. Cant be the master cylinder.
Cant find any leaks at all, triple checked all nipples, joints and hoses and its fine.

The VW mechanic who helped me yesterday used to work at Audi back when these were new and worked on a few since, he was very sure its the accumulator, but up to me if i buy a servo as well.

The pedal is hard when engine is off but when started its goes to the floor with slight resistance and juddering.

[ChrisG]

unless a faulty master cylinder !
OK so go for accumulator.... and when this is finally working I shall have to come and see the car......take me about 30 minutes to get to your area : )

[saladdodger]

Originally Posted by ChrisG

unless a faulty master cylinder !
OK so go for accumulator.... and when this is finally working I shall have to come and see the car......take me about 30 minutes to get to your area : )

i'll let you know when its fixed mate

[missfire]

Originally Posted by TeXerv

My two cents from the distance:
In deed the accumulator is worn. Less or none nitrogen pressure inside. This can cause an juddering pedal when engine is running (you feel the two pump pistons and the pressure control working).
But a worn pressure accumulator never makes the pedal decrease during actuating. Opposite, it makes the pedal feels hard and it shortens the pedal way.
Declining brake pressure must be caused by a leak, intern or extern. In your case I'd suggest the master cylinder.

Spot on yet again! The beeping noise is the 'servo fooked' warning sound, all of mine do that after three pumps, brakes still work fine. Going to floor has to be master cylinder of something wrong inside the abs unit?

[TeXerv]

Originally Posted by missfire

The beeping noise is the 'servo fooked' warning sound, all of mine do that after three pumps, brakes still work fine.

You know that your pressure reservoir is at it's end? It usually should allow 20-25 break actuations until the warning comes.

[pimpdriver]

Originally Posted by TeXerv

You know that your pressure reservoir is at it's end? It usually should allow 20-25 break actuations until the warning comes.

http://www.sjmautotechnik.com/troubl...rake.html#bomb

[saladdodger]

This is getting ridiculous now, im damn sure its not master cylinder it brand new and pumps well, how can all this go wrong with a simple caliper(s) change. Seriously

[missfire]

Originally Posted by TeXerv

You know that your pressure reservoir is at it's end? It usually should allow 20-25 break actuations until the warning comes.

Yes! I know that, none of them work, I have three of them. I'm not buying three.

See what you mean now saladburger, just had a look, servo must be cheaper than an accumulator! There is some kind of valve inside the accumulator too that can stick too I think, so... money either way.

No chance you popped a seal somehow in the master cylinder when it was fitted?

[missfire]

Originally Posted by saladdodger

This is getting ridiculous now, im damn sure its not master cylinder it brand new and pumps well, how can all this go wrong with a simple caliper(s) change. Seriously

Take it to Audi and get them to bleed it.

[saladdodger]

Originally Posted by pimpdriver

http://www.sjmautotechnik.com/troubl...rake.html#bomb

Its not the small brake light that comes on it the big LCD panel thats flashing/beeping