Audi 80 B4 brake problems

[Audiden]

As usual, here I am again asking for help with my 80 Avant 2.6 auto

Well iirc the brakes have always been crap since owning the car, so have been used to them thinking thats just how they werein all 80's. When I got the 90 I realised this wasn't the case as the brakes in that were very good.

Anyway, short of replacing front discs & pads and the front brake hoses, it's had nothing done on it, but the car shows various symptoms of their being underlying faults...

With the engine running:

1.The brake pedal when pressed, will go the normal travel down, but can be shoved further all the way to the floor... kind of in a slight jerking manner.

2.When coming to a normal stop the brakes work as usual, but if you release the pedal & brake suddenly after that it's as if there is no servo assistance.

3.The brake warning light has recently started flashing when light brake pressure applied when on the move.

4.The power steering pump has always been whiney (like me? lol) and groans when parking (not like me )

5.With the steering on full lock with engine still running, takes one or two presses before the pedal hardens.

Other symptoms are:

6.There was a loss in PAS fluid 6 months ago, I topped it up with the correct stuff & it's never lost any ever since.

7.The brake pedal is pretty hard all the time when doing the brake bomb test, but hardens up a bit more after 20 presses.

And this is above & beyond all the cars other issues and whilst the car is still safe to drive imo, it really does need sorted.

[missfire]

dunno man, sound like pump and bomb are goosed to me. its the only system in these cars that i hate. wish i could fit a vacuum servo to mine but there is no room as far as i can see.

the fluid loss may have been the 'cavity' in the bomb filling up with fluid, where the gas charge once lived. (nitrogen charge? i think 1300 odd psi.) it percolates either through or around the diaphragm over a period of a decade or so, supposedly. i think the diagphragm might act as a damper for the pump also, when its full of gas, so you might be feeling the 1 remaining piston () labouring away through the pedal.

shit system!

[Audiden]

Hmm, thank-you for your comprehensive answer which I think covers all the faults Well luckily I have a spare pump & I was getting a brake bomb sorted but unfortunately my one is the rarer type Just like the one I sold for cheap earlier in the year

[mikes2]

Best to check the servo first.

disconnect the return line - there should only be a few drips in there. More than that and the servo is leaking

[Audiden]

Originally Posted by mikes2

Best to check the servo first.

disconnect the return line - there should only be a few drips in there. More than that and the servo is leaking

I shall have a look at that, cheers