Soft Brakes

[Nilz]

OK so I noticed my brakes had gone soft a few weeks ago all of a sudden, so I did a full brake fluid change, bled all the brakes and the master cylinder, whilst doing this, I noticed the rear pads were VERY low, so I changed them as well, but the brakes still feel very soft, so I bled the MC again today, but still no difference, they still feel like they are not quite there (if you know what i mean).

Does anyone have any thoughts or ideas on why this has happened or how to sort it

Its a 2002 AMK S3.

Thanks in advance.
Nilz

 

[a3tdi2001]

Might sound ridiculous but I had a similar problem after having the back axle off to do the bushes. The brakes came back into their own after a couple of days driving. Maybe some air was trapped somewhere?

 

[Nilz]

Its been 2 weeks since the fluid change and a week since the pad change too.

Also, i noticed that my handbrake was sticking a while ago, my drivers side rear pad was totally flat, as I think it was sticking to the disk, the passenger side was fine and there was plenty life left on this side.

Released the handbrake, WD40d it and that seems to be ok now, still the brakes dont seem to be there tho!!

Think its worth rebleeding all the brakes and MC again?

 

[a3tdi2001]

Could be worth bleeding them, but I'm no expert to be honest. I read in the Haynes manual for the A3 that they should be done in a certain order but not sure how important that is. Are you using a pressure bleeding kit or getting someone to give you a hand?

 

[Nilz]

Ive been doing it with my uncle who is a mechanic, im pumping the brakes, while he is bleeding them.

 

[a3tdi2001]

Could there be a problem with a sticking piston on the driver's side rear or does the caliper definitely release after you press the brakes? Just wondering if you might have tested with applying the handbrake and thinking it was releasing fine but it could be sticking when you use the brakes?

 

[Nilz]

No its releasing fine now, checked all of that and its all ok now.

 

[aragorn]

Try using a pressure bleeder rather than the old-skool pumping the pedal method.

It could be a faulty master cylinder, or a leak.

 

[jojo]

Nilz, let me know if you need to borrow my pressure bleeder, it's so much easier and I manage to do it on myself. Instant brakes back on the S3 I sold to Gops!

 

[Metro]

Have you checked the brake booster pipe coming off the inlet mani? My brakes were foobed a while a go and i sorted it with a bit of insulating tape around a crack in that vac pipe

 

[Greig300]

Soft brakes on my S3 meant Brake master cylinder is the fault. Whole unit has to be replaced. Quite common on Audi 8ls & TTs.

 

[Nilz]

Jo, will need to give you a shout if you are free to give me a hand with this, I need to check the pipe as well....is it the one on the left hand side, if you are looking into the engine bay, im pretty sure i replaced all of that recently, so hopefully not that.

Noticed my handbrake has started sticking again yesterday!!

 

[jojo]

Jo, will need to give you a shout if you are free to give me a hand with this, I need to check the pipe as well....is it the one on the left hand side, if you are looking into the engine bay, im pretty sure i replaced all of that recently, so hopefully not that.

Noticed my handbrake has started sticking again yesterday!!

Not had much time to work on my own car! lol

Lets try Thursday night?

 

[takworldwide]

I have exactly the same problem rear o/s on my a3 1.8t. i have changed discs/pads and eazi bled all lines in the correct order and still the same! i have also replaced the vac pipe going into the brake servo(as it was split). i have ran out of options! was just about to live with it when i came across this thread.

i hope someone susses it out, please please let me know.

Tom

 

[Nilz]

Cool Jo, will give you a shout in the day, as im off then anyway.

Tom, we will let you know what happens.

Have you bled your master cylinder, as you havent mentioned that above??

 

[takworldwide]

Cheers Nilz, i bled the 2 nipple underneath the reservoir (i think its the slave cylinder). does the master cylinder have a bleeding point?

 

[Metro]

The master cylinder sits under the fluid bottle and that has two nipples. Tried cycling the abs pump using VCDS?

 

[takworldwide]

sorry dude, I'm getting master and slave mixed up! I bled the 2 nipple under the brake fluid reservoir(they are a nightmare to bleed without getting fluid everywhere). looks like i'll have to wait to see what nilz finds.....

 

[Metro]

Seriously through, if your having problems and have tried everything apartment from cycling the MC, I'd get it done..

 

[Nilz]

The master cylinder is the one in the engine bay, top left hand corner next to the brake fluid bottle.

To be honest, my brakes feel like they are back as they were now for some reason, however my handbrake is still sticking, so am going to get my springs tomorrow and see if I can get them fitted this week - see the other thread about that.

 

[Metro]

Good to hear your back up and working.

 

[Nilz]

I needed my brakes earlier when some tw@ pulled out from behind a tractor to overtake it and came head on towards me without checking if it was clear or not, luckily he got back into his space, otherwise, I would most probably not be here typing this right now!!!

 

[Metro]

That's the time when you need a front mounted RPG cannon... Why won't someone do a built thread on armouring an s3 8D

Do I need to get out more?

 

[jojo]

I needed my brakes earlier when some tw@ pulled out from behind a tractor to overtake it and came head on towards me without checking if it was clear or not, luckily he got back into his space, otherwise, I would most probably not be here typing this right now!!!

Maybe you activated the ABS during your emergency stop, this sometimes brings the brakes back!

 

[Dane]

Another vote for a tired MC

 

[Nilz]

Well im hoping as Jo has suggested that maybe the ABS has sorted them, but will see how it goes and update accordingly.