Long brake pedal travel

[<tuffty/>]

Started to notice my brake pedal travel getting longer over the past month and put it down to needing a fluid change. Replaced the fluid yesterday with Motul 600 and still no better.

Took the car to a friend who has a vacuum bleeder and now I have a bit of a pedal but it still goes pretty much to the floor.

We cycled the ABS through VAGCOM, checked brake pressure through VAGCOM and all seems good.

Pump the pedal when the engine is off and the pedal goes nice and hard and holds, start the car and it sinks to the floor.

I have run out of ideas on this, we have re-bled the entire system twice now so there can't be any air in the system...

Anyone have any ideas? I really do not want to leave my car in the hands of a stealer as I am sure this is fixable.

<tuffty/>

 

[HTC]

When starting the car with your foot on the pedal it should sink. This indicates that the servo is working okay. But it should return when pumped. It won't be as hard as when the engine is off. This is normal.

However, I would also bleed the nipple at the master cylinder and check for leaks.

 

[s3_kev]

yeah my pedal was really long after my brake pipe broke, it took me 3 attempts to bleed the brakes it was better once i had bleed the nipples at te master cylinder, then i went up the road and stamped on the brakes to get the abs kicking in then slowly the pedal has returned, have you replaced any brakes at the same time?? as they will need bedding into so would give a slightly softer pedal to

 

[Effect]

we have re-bled the entire system twice now so there can't be any air in the system...


<tuffty/>

You have no idea how wrong you could potentially be with this statement.
I ended up spending in the region of £600 at 3 different places getting my brakes bled up before I finally got them sorted.

Some VAG cars are justa complete bitch to bleed up properly.
The place that got them sorted for me in the end was the most expensive but even they struggled.
How out of your way is Nottingham ?

 

[<tuffty/>]

Miles away mate, thanks anyhoo... Now the pads have bedded in a bit I seem to have some brakes at least... I have some braided hoses on order for the front brakes so going to sort my pressure bleeder out to sort them and also bleed the master cylinder as HTC and others have suggested.

There is a rather lengthy procedure in ElsaWin using a pressure bleeder and VAGCOM which I might try when I change the pipes.

Just glad Bill at Badger 5 has got a load of Motul 600 in!!! (although as glad as he will be when I buy another couple of litres of the stuff!)

 

[Crazypete00]

ye i had this problem, found out under the bonnet that something was rubbing my brake pipe and caused a tiny hole, when braking it would shoot out fluid which would not give me very good pressure on the brakes. check the brake pipes in the engine bay for any little holes when braking

 

[Trick]

I had the same thing, but turned out to be one of the rear calipers had seized and was vapouring brake fluid. un-seized it, bled it and it was back to normal.

 

[<tuffty/>]

Hummm, I need to change the rear discs and pads soon so I'll double check that... thanks

 

[<tuffty/>]

Righty... changed the rear discs and pads... word of advice buy or at least hire/borrow a brake piston winding tool... I usually use pliers but no joy with these!!

Got it all together and I have my pedal back!!! the discs were well worn and the pads had about 2mm left...

I am glad my pedals come back but I think I will re-bleed the system including the master cylinder as a precuation.

Seems an odd way to let you know you have no rear brakes by giving you none!!!

 

[<tuffty/>]

Could someone let me know what size the master cylinder bleed nipples are please? They look to be 7mm..

Ta

<tuffty/>

 

[<tuffty/>]

Just when I thought I had this, its still not right... the pedal still has loads of travel and I have re-bled the brakes again including the master cylinder (what a ****** to get too!!)

Any suggestions?

 

[s3_kev]

did you do both nipples on the master cylinder, i realsed this after bleeing my brakes now i need to do the one i missed guurrrr

 

[<tuffty/>]

yeah, did them both... now put over 3ltrs of Motul 600 through um

Funnily though once the DS2500's get a bit of warmth in them the braking effort is pretty good but the pedal is still pretty much to the floor which doesn't give much confidence tbh...

 

[<tuffty/>]

Does anyone know any VAG/Audi technicians that they could ask for any ideas on this please?

I have exhausted everything I can think of bar changing the MC itself which at over £100 in what looks a knuckle scraping procedure, I would rather seek some further advice if poss...

Happy enough to swap it out if it will fix it but would like a little more input before I embark on that adventure

Ta

<tuffty/>

 

[krislou80]

First make sure the master is full of brake fluid and no loss of fluid. If you have drums in the back, did you adjust them properly, spin drum by hand and adjust till they are a little tight. Next, if all that is good, it is possible that the brake master is by-passing. For that, you have to replace the master. Make sure to bench bleed first.

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[5teve L]

My S3 is the same, once you get used to the extra travel & know that the brakes actually work very well it's ok, well I'm used to it now. I also tried bleeding the whole system inc master & clutch, a little better but not how I'd expect it to be. I need to change the rear pads & discs so I'll fit the rear braided hoses & re-bleed again, I may try some motul this time.
For the record I bled mine twice as well with no great results so I'd be interested in your findings.

Steve

 

[thegoal007]

Just read this thread, but I thought the obvious answer to your initial post should have been to check your brake pads. Not sure why no one mentioned it. As the front ones have a sensor then the rear ones require inspection. Every car I have owned I have relied on checking the brake fluid level going down as a prompt for me to check my front and rear brake pads/disks. I certainly would not have just simply jumped to replace the brake fluid or topped it up (unless dangerously low) - sorry maybe it's just me, but it just seemed so obvious to check first.

 

[Imteyaz]

I don't know if this will help but on the old MKII Golf's, you had a brake compensator valve attached to the rear axle. If you didn'y manually open the valve (see pic below), brake bleeding would'nt cure the long pedal travel. Open it fully and the air would pass through when bleeding.

(pic shamelessly stolen from Club GTI.... Linky to post: http://www.clubgti.co.uk/forum/showthread.php?t=219024&highlight=bias+valve)

Do A3/S3's have this? If they do, I would try that to see if it helps. Also, the brake fluid reservoir on the A3's is used to supply fluid to the clutch, is there a possibility of air in the clutch system somehow causing the inadvertant long brake pedal travel?

 

[s3dave]

this post is from ages ago, im sure he would have them sorted now??....lol

 

[5teve L]

I'd be interested to know if he has