Bomb change brake still hard

[robinm]

Well done. Did you get a new audi servo?
Did you have to remove half the dash or could you get at the nuts from the footwell under the pedals?
You've changed everything else so must be the PAS pump that isn't delivering sufficient pressure. Do you still get the three bleeps after starting?

[maRS2]

It's very easy to change.
The brake servo seat on a black metal bracket that have 3 screw on the other side close to the brake pedal.

Undo those 3 screw
remove clip that old to the brake pedal
remove spring on thhe brake pedal
take out all hose plumb to brake booster and master cylinder.

20 mn later you have the part in your hand.
change it and put evry thing back again opposite way.
then a good brake fluid bleed and you done.

[maRS2]

No bleep, just OK after I first touch brake pedal.
No more bleep on bump also and I did not refill the powersteering fluid.

Yes bought it from Audi with 20% discount about 600€ with VAT. that hurt.

[robinm]

Wow that's expensive. Does it look like it might be possible to recondition the servo? ie replace rubber seals and the one way valve. I wonder why it costs so much.
Rob

[maRS2]

So just changed the PAS pump for a new one.

So now bomb, PAS pump and servo brake are new plus pressure hoses.
But still after 5 to 8 pump on the pedal it goes hard even with engine on, if you leave then the feet on the pedal with engine on you can feel it juder and get slowely soft again.

I had the warning light coming on again also on bump thought it was the PAS fluid level sensor so I disconect it to see if the light stop coming on. It didn't.

Then I disconect the sensor for level of brake fluid and their the warning stped to flash on bump. So this one is the problem for bump warning flash.


Do some body have any idea why my brake pedal go hard even with engine on after a few pump.
the last part i din't change is the master cylinder. Could it be that one?

[maRS2]

Could it be that the new bomb that i got from Audi was also dead?

Is their an other way to test the bomb than the pedal pump thing?