Hard brake pedal

today was at a supermarket carpark and was reversing in a space pressed the brake pedal and it was hard car was rolling back panicked a bit pressed it a couple of times and it was working weird read alot about water in the plenum chamber so checked that first thing and could not see any water felt under the battery and pulled out a rubber bung size of a 50p piece there is also one under the brake servo but can't get to it just thinking what I should do next a bit scared that it will happen again at higher speeds mind you yesterday it rained really heavy and car was left parked did not drive all day yesterday had the car since 2008 first time I had this issue car is a audi a4 54 plate 1.9 tdi 115 BKE any advice people thanks

I had the same problem with my 1.9 b7(same engine code) and it turned out to be(like you sugested)the plenum chamber filled with water.i managed to unblock the drainage under the servo with a bent wire but couldn't reach the one under the battery.took it to a garage just to make sure it was the water that caused the brakes to faill.unfortunatelly in my case i found out about the problem the hard way,when i stopped in the bumper of the car in front of me.that was 2 years ago and once the two drainage holes were unblocked everything has been fine since.i too had the incident on a rainy day.you can try and pour some water yourself(not a lot)and see if that draines underneath the car somewhere.since the incident i check mine as often as i get a chance.good luck in sorting it out.

How do you get to the drain hole under the servo

i reached mine with my fingers first(i don't have the sausage type of fingers)and once i knew roughly where it was i than put a length of wire,bent at the front and managed to poke that through the drainage hole.it wasn't too hard as both the battery and the brake servo where half way up in water and as soon as i poked the drainage hole i could see all the water draining underneath the car.like i said just try with your fingers first to a have a feel for the rubber drainage hole and once you find it try with some wire or something.

Unless you have a middle digit as long as E.T's, you can use a long extension bar from a socket set or a flexible piece of tube etc. if you shine a torch under the servo from the right hand side, you should just be able to see the rubber drain grommet. Mine under the battery was removed by Audi during one of it's services, the one under the servo i check regularly with the obove method.

So keep the drain holes free from dirt and stuff should not get this problem again or is the servo know damaged

Once water is in the servo that is the end of the servo and no amount of plenum chamber drain poking will get water out of the servo.

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Originally Posted by Crasher

Once water is in the servo that is the end of the servo and no amount of plenum chamber drain poking will get water out of the servo.

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Ok crasher thanks any chance you could get the part number for the servo for me cars a audi a4 1.9 tdi 115 sport BKE 54 plate il pm the vin if you want it thanks beforehand mate

Quote:

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Originally Posted by Crasher

Once water is in the servo that is the end of the servo and no amount of plenum chamber drain poking will get water out of the servo.

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Every time I check the area by the servo and battery there is no standing water there could it be the vac line to the servo damaged or split is there any way I could check that vac line this had only happened once had the car since 2008 Any pics for the vac line would be great thanks

Removed the rubber bungs under the battery and servo the one under the servo had a pipe going through it so left it hanging on bit tight to get to the one under the servo but managed it battery one was easy