s4 quattro braking problem

[manji]

I recently had the brake warning light and the beep come on when I was driving home the other day, when i got home i checked the fluid level which i topped up, it only took a lid full.

I started the car again but this time none of the warnings came on i drove it round the block and as i was driving round it beeped and the warning light came back on, when i went to brake there was brakes there but really slow at stopping.

There is pressure on the pedal but not the normal stopping power, I got the car on the computer but its not coming up with any faults, checked the pads etc all seem to be fine. I have been told that these cars have a electronic servo?

The car is a year 96 model. any help would be appreciated.

cheers

 

[aragorn]

three beeps and a big (!) is often an ABS fault...

 

[manji]

I will have to check again I know there was three beeps at least. I will check when i get back tomorrow, if it is a ABS fault should it still not come up on the computer?

cheers

 

[aragorn]

it should, but you will need to specifically scan the ABS controller for faults.

Theres also a common fault with the controller where some wires inside break, causing it to fail. If thats the problem it probably wont respond to the scan tool.

 

[manji]

Thanks I will check tomorrow and post results

 

[manji]

Hi I have checked it is just 3 beeps all the same.

One thing that i forgot to mention if you put you foot on the brake pedal and start it it should start off hard then go down a bit, but with this it stays hard.

 

[aragorn]

The pedal staying hard is indicative of a faulty brake servo... But thats unlikely to give you the three beeps...

Check the vacuum feed to the servo hasnt come adrift.

 

[manji]

I will have a look tomorrow. thanks

 

[Audi2ptzero]

Does the car pull to either side when you first hit the brakes?

 

[manji]

No it does not pull at all to any side.

Does the car pull to either side when you first hit the brakes?

 

[manji]

Hi I have been having a look but I cant seem to find the servo in the normal position unless it is under the dash. Do these cars not have a full electronic braking system including servo?

Also would the car not rev up and down if the feed had come adrift?

cheers

The pedal staying hard is indicative of a faulty brake servo... But thats unlikely to give you the three beeps...

Check the vacuum feed to the servo hasnt come adrift.

 

[aragorn]

No it has a standard servo and hydraulic master cylinder. No electronics at all.

The servo is beside the battery. Its feed runs to a "port" on the bulkhead, and then into the rear of the inlet manifold

 

[manji]

ok will have another look tomorrow. just to make sure it is a 96 s4 estate quattro.

cheers

 

[aragorn]

The B5 S4 wasnt released until '98 in the UK...

 

[manji]

sorry not too sure all i know is it is a s4 quattro estate 5 cylinder turbo. the battery is under the back seat. could this be a c4?

The B5 S4 wasnt released until '98 in the UK...

 

[pjw]

Dont think its a b5 with the battery under the back seat.

 

[manji]

it looks simlar to this in the log book it say audi 100 advant
http://http://upload.wikimedia.org/wikipedia/commons/9/99/AUDI_100_C4_Avant-92.jpg

 

[pjw]

Ahh if its a 100 you want to be posting here mate : Classic Audi Forum

Sorry i havent got any experience of the 100.

 

[aragorn]

Yer, as above its a C4 A6 chassis.

I'm not sure the best place to ask for help with that tbh, the classic audi section on here isnt particularly busy.

 

[manji]

ok thanks for you help guys.

 

[GSB1]

I hope this forum is sucessful enough for nobody's nose to be out of joint at me suggesting Classic Audi Online in order to help someone. The experience in that era of car might be just what you need.