Brake problem!!!!!!

[5up3rman]

Driving in to work today and then all of a sudden it felt as if my car was being held back slightly. As i'm stuck in slow moving traffic, i have the cluth down and am cosating along but notice that it seems to be slowing down until it actually stops wityhout me breaking. i can actually feel the brakes engaging.
It doesn't feel liek front brakes but rears.
i pull into hard shoulder and turn off and check things and all seems ok, but it definately is a problem.
I get to work a few miles later, and go to check the driver side rear wheel and can distinctnly smell brakes!
I'm really worried as i need to get home obviously but at the same time i dont wanna ruin the car. any ideas whjat can be the prob???
Desperately need some help

[nevo]

Two possibilities,firstly the hand brake is siezed not releasing the pads,secondly you may have a siezed caliper, can you smell burning brakes both sides?(are they hot!) if both sides are smelly its unlikely to be both calipers gone at once. Jack up the car and spin them by hand.

[5up3rman]

hi and thanks for the reply.
not had a chance or ability jack it up right now so can't test turning the wheel.
But i wanted to take it quickly down to the shops to see if it was still locked on.
i pulled up the handbreak a little hatrder than normal and it seems now that the brakes arent locking.
When i checked in the morning after i was experiencing the problem the brake on the driver rear side was smelly and very hot, but not on the passenger side.

I was just looking aroudn the car at all the other pads, and i was just wondering, how much space is there generally between the pad and disc?
my front and rear pads are both pretty much new.

[5up3rman]

ok this is so annoying!

the car has the feeling that something is slightly holding it back and is coming to a gentle stop by itself when i coast.
So i drove the car home from work about 17 miles. i was going to show it to a mechanic friend.
It happened all the way home right up until one turn from the guys house!!!!
talk about sods law!

he jacked it up and checked all the wheels by turning them, and they all turned fine, this could be to go with the fact that the problem wasn't occurring anymore.
However the front passenger wheel was very hot and smelt of brake.
not the rear driver one as i had smelt in the morning.

Since the problem wasn't occurring there isn't much we could do.
If it does happen it was most likely to be a seized caliper and will need replacing, he thinks.

Gonna do a scan with vcds the free version and see if anything comes up, i have a feeling it won't though.
It does have me really worried though and i just hope it was some kind of freak one off problems

[5up3rman]

so i did a scan yesterday evening, all be it freeware version of vcds.
anyway as expected no fault codes came up in regards to this.
as mentioned in previous post the fault wasnt occuring with my mechanic mate.
so i left for work a little earlier today and wasn't ecperiencing the same problem.
thank god i thought, however once i hit the motorway i started to get a noticeable vibration once up to about 60mph.
it wasn't the road surface but i don't know what it was as this was something new and also i didn't appear to be having the brake issue.
only a few miles to work so i took it easy and got there.
got out the car and smelt and looked all aroudn the wheels and i can say the front two wheels were really hot and smelt of brakes, the rear driver side was not so bad but still had a little whiff and the passaenger side rear was completely fine no heat or smell.
what the hell is my cars problem
again sods law will be the fault wont occur when i take it down to a mechanic.
any thoughts on this one guys?? i'm really a little stressed about this.

thanks

[zollaf]

so, you have an intermittant brake sticking on problem. things that can cause this are: caliper piston corroded (pull back rubber boot to see ), caliper sliding pins sticking, brake pads seizing in carrier, rubber brake hoses perished inside, acting like a one way valve, causing fluid to not return, or on the rears, seizing handbrake cables. i have also seen discs with a lip grab the pad as well, causing the same fault. so, all wheels off ground, firmly apply brakes, release pedal and see which wheels dont instantly become free. apply handbrake and check for same. it would also be worth a strip and rebuild of calipers and carriers. this involves removing the caliper and pads, cleaning things up, paying attention to where the pads sit, then extracting the caliper piston to near the end of its travel (gently pump pedal, piston moves out, but not all the way), pull back the rubber boot and check for splits in it, or corrosion on the piston. if with this done, the fault remains, change the flexi hoses. after that then it must be a fault with the master cylinder/abs unit, but unlikely.

[5up3rman]

ok wow thanks for the quick reply.

i was confident yesterday the brakes were sticking however today mornign it didnt seem like it though the smell and heat from tyres would indicate otherwise.
The new thing thats worrying is the vibration, this wasn't happening yesterday.

I think checking all the things you mentioned below are realistically beyong me doing myself.
I'm gonna have to bite the bullet and give it in to a garage, just a matter of finding one in the Slough area thats good and trustworthy.

Thanks

[zollaf]

intermittant faults like this can be a mare to find. a vibration can be caused by a sticking brake. from experience, intermittant faults like yours are often down to the piston sticking in the caliper. everything else usually causes a constant fault, which is easy to find, (which wheel wont turn ?). also, due to the time and difficulty it takes to correctly identify the fault, a garage may have to fit new parts and hope, starting with whatever looks suspect. this often isnt the right part , so the fault remains. i have had it, you think you have it sorted, then 3 days later the customers back and its done it again, exactly the same. (that one was a caliper on an isuzu, very expensive).
good luck, i hope they can find it.

[5up3rman]

Thanks a lot mate.
i'm assuming it is a caliper piston fault, but i would have thought it would lock totally and that would be really noticeable.
This seems to be almost as if the brakes are just very slightly on.
i also did a test off pressing down the brake pedal and then switching engine on. the pedal went down a bit further so my mate told me that means the brake servo is working.
i just hope they can find it and i hope the bloody car doesn't play up and it actually produces the fault when the mechanics have it.

is A.V.I.T in slough a good place?? anyone used or can recommend them?

Thanks

[nevo]

Very strange the problem starts on the rears then the fronts,could be an ABS problem,the unit may be modulating the wheels via the ESP,hope not for your wallets sake,try all the cheaper options first as detailed above,good luck,give us some feed back.

[5up3rman]

would it be worth trying to turn esp off and then see what happens.
i know the switch doesn't totally switch off esp, but would that be able to help in anyway?

[nevo]

Give it a go as long as you dont throw it about ,as I say very strange,you,re going to have to get it up in the air and get the wheels off.You can't see the pads back off visibly there in constant contact with the discs,spin the wheels and get someone to press the pedal then release ,see if they spin again,(with ignition off so abs wont interfere)..Dont think you've got a sticking caliper though,if the problem is moving from front to rear and visa versa,could be the master cylinder sticking,even though the pedal has returned to its stop

[5up3rman]

it was jacked up yesterday evening, when i took it to my mate, and it had just stopped doing the poblem then.
all wheels seemed to be spinning fine.
will try out the brake spin release spon thing you said though.

thanks
will let you know, i'm really praying that this isnt a big problem

[kite]

Good garage in the slough area.

http://www.theautopool.co.uk/

[vwcabriolet1971]

It has been known that on cars which havn't had the brake fluid changed for some time a condition called "vapour lock" can happen. What happens is that because the brake fuid has absorbed more than normal amount of water , the boiling point of the fluid/ water mix is lowered . During heavy braking it is possible that the fuid mix may boil and the steam generated expands and locks the brake hard on .
I'm not suggesting that this the case in this example but something to bear in mind.

[nevo]

5up3man,being thinking,this is what I want you to try,drive the car and when it starts sticking place your foot under the brake pedal and lift it up to be sure its on its stop.

[fourringsrus]

I would echo all that zollaf says and add that if this "sticking" is moving from fronts one minute to rears the next, you may be looking at a faulty master cylinder.

Stuart

[5up3rman]

Thank you one and all for all tyour thoughts and opinions.

So had it in at the garage today in Slough.
Took it down to A.V.I.T, and have to say they're a good bunch of guys.

As of this morning the brake problem which was my initial problem wasn't happening, however i still did have the shaking/vibration at speeds of 60 and above.

Left it with them for the morning, called me in the afternoon saying they had not found any problems with the brakes or the car in general.
was jacked up first of all and all wheels were spun to checl and they were ok, visual check of pads and calipers and all was fine.
they also did the MOT brakes test at an MOT station with one of their guys.
then was taken on a test drive to check for brakes problems and vibration.
no faults ocdured on the test drive.

I went to pick it up and also went out with the guy for a test drive and none of the faults occurred.
I don't know what it is or was or why it's not happening.
God only hopes i didn't imagine or i'll be checking myself into the funny farm.

I can only monitor and see if problem reoccurs.

[nevo]

These sorts of faults are a nightmare,everyone thinks your imagining it,don't worry the men in white coats are not coming!you know when your cars not right,my hunch is you may have a sticking servo,the pushrod and pedal not returning fully to its stop(intermittantly)just by a few millimetres,but enough to cause some slight braking and heat!,but also a sticking M/C is also plausible seeing as you said 1 rear and 1 front was getting hot (oposite corners is one circuit).All you can do now is monitor the situation,I think we're in the right area,but if it returns you're going to have to start changing some parts,what to go for first is the $64k question.If you go for the M/C ,the servo is nearly off anyway,its just so costly to change parts,with your fingers crossed.Keep us posted,getting to the cause of problems like this can a lot of grief for others.

[5up3rman]

yea since we're in the scary area of costs of parts.
what is the going price of brake servo and the master cylinder?

something for some reason, not any professional knowledge is that i'm thinking its not the servo but more likely master cylinder.
thats just going by what you saying is plausible.

[Dazzler01]

Hi,After changing my front disks and pads,I too have noticed a vibration about 60mph and when you brake-you get a severe vibration through to whole car and the gear lever vibrates badly,my ns front is hotter than the other and has worn the pads much more than the offside,im suspecting a partly seized caliper-i have a appointment booked with a local brake specialist on Wednesday,will let you know how I get on,but we both have the same faults !!

[5up3rman]

Mine has suddenly vanished.
i think the brakes are slightly hotter one side to the other but
i have forgotten to check over the last few days so not entirely sure.
but i still think there is some underlaying problem.
would definately love to hear what you find out with your problem and most of all i hope they can solve it for you and it doesn't cost you too much.

[nevo]

Vibration under braking after fitting new discs could be the new disc in question not been fitted correctly(check run out with a DTI)the hub must be cleaned with emery paper on its mating surface,also over use of copper slip on the hub surface can also cause problems with discs not running true,are you getting any pulsing through the brake pedal?.

[Dazzler01]

On the way home this morning I to had noticed that the vibration had also gone,the brakes were cool after driving 30 miles home,I'm thinking that the prob is most likely to be that the nearside piston is not releasing fully,i'm keeping my visit to the brake specialist to see if he can provide anymore input,cleaned all mating surfaces with emery paper,esp between disc and hub and the caliper were the pads sit,just to make sure,will check brake temp today going to work and update you further tomorrow night !!!!

[5up3rman]

hey dazzler
did you ever see the brake specialist guy?
any joys or any further news/updates

[wanalaugh]

Guys...sorry if I cover some of the same points already discussed on here. But there are far to many posts to read through.

I had the same problem with the brakes binding - staying on, to teh stage that I couldnt drive any faster than 40-50mph. Without writing the full story, my car needed and master brake cylinder and servo.
MBC - 125+vat
Servo 165 of ebay (new)

The brake now work perfectly although taking the brake pedal out had caused me a few problems with a faulty brake switch causing the ESP and pre heat light coming on arghhhhhhhhhhhhhhhh.

The cause of teh fault was water building up where the servo is housed and is a common fault in Audi (mines a 2002 TDI). Before u put all the new parts in, take out the two rubber grommets in this area so teh water freely flows, or u will get the same problem, water ingress into the servo...

Hope this helps...

Ricky

[Mr Tickle]

The vibration imo would more likely be your wheels out of balance. I've had those stick on weights come off in hot weather. Although this vibration would be present all the time and not intermittantly.
Try cleaning your caliper & piston & mentioned above. A slight smear of copper grease does wonders.

[tyberwan]

I have had a similar problem. You may either have a problem with the master cylinder or servo.

The vibration comes from the sticky brake pads and after driving for some time, either your brake disc has become slightly warped and transferring this through your pads sticking. When you brake, this vibration disappears slightly and will come back if the brakes are sticking.

When you start your engine, the brakes are fine. They start sticking after 15 mins, then go on forever until you switch off you engine and on again, you hear a small "clunk" and it seems to be released a little bit, but comes on sticking again almost immediately. Sometimes when you drive with the brakes sticking, after some time, it cures itself and you do not feel the binding. But it comes the next day...

You will then notice that one brake pad wears much quicker than the other in the front...

Some mechanic said it's may be the abs unit, but your abs light does not come on. However, how is the servo damaged? I would have believed that when it's damaged, you cannot press the brakes as it should and brakes would be either rock hard or no brakes at all?

[spartacus 68]

On the way home this morning I to had noticed that the vibration had also gone,the brakes were cool after driving 30 miles home,I'm thinking that the prob is most likely to be that the nearside piston is not releasing fully,i'm keeping my visit to the brake specialist to see if he can provide anymore input,cleaned all mating surfaces with emery paper,esp between disc and hub and the caliper were the pads sit,just to make sure,will check brake temp today going to work and update you further tomorrow night !!!!

You can use Lockheed red grease (specially formulated for hydraulic applications). Two options, either a complete caliper strip down (I know it's a pain), and smear red grease on inside of piston bore, fit new 'o' ring, etc. Or, a quicker option - is to remove the pads and discs and press the brake a few times to extend the piston, then apply red grease under the dust sleeve. Be careful - or you'll end up tearing it. Also worth checking the caliper slide pins are lubricated, with no surface corrosion.

[5up3rman]

I can say that since i commented on the problem happening, it hasn't come back agaain.
Apart from yesterday after driving about 5 miles at the end of the day.
i reached my destination parked up and switch off engine, 2 hours later drove away problem didn't happen.

It's the strangest thing!
Very very intermitant, nobody can find a problem that has had a look at it, especially as the problem doesn't rear it's head when taking it to a garage!

I wait for someone to come up with a definitave answer.

[maxell]

Also experiencing the exact same problem.

Driverside rear brake sticking on and the handbrake lever having a different feel to it than normal (very loose at the first few clicks suggesting its siezed on slightly)

Changed brake caliper and both handbrake cables but no such luck, I also notice it seems to occur when there is a severe cold snap like we have now.

My car is a 2.5tdi quattro.

Has anyone been able to work out the issue as of yet?

[wanalaugh]

Hi
This doesnt appear to be the same problem i had. My issue was that the
front brakes where binding and sticking on. So was wearing the pads and discs. Until eventually they seized completely. The problem was the brake servo. There is a current recall to have two little rubber grommets removed from the chamber below the windcreen where the servo is located. The grommets are blocking up so water gets trapped and causes the servo unit to rust at the bottom. This causes it to loose its sealing capacity, and then sucks in water under heavy braking...Now you have water in your servo....When its cold, the water freezes and makes your brake fails....I repaired mine for around £600. This was for the servo and master brake cylinder (servo from ebay was £163 and master brake £125). Now the good news - Audi contaced me ref the recall on teh grommet, but I told them that I had to do this repair....and guess what - They refunded me my 600 pounds :o)

If you need any further info email me at rickyni73@hotmail.com
As im not always on this site.

Ricky

[rocker55]

I also had a recall letter in August 2010 and didn't bother with it as I had removed the bungs in 2006 not long after I bought the car.

Yesterday the brake pedal went hard and I nearly ******* myself into a roundabout. luckily no-one was coming and I managed to drive round it, although more at speeds I haven't done through a roundabout in almost 20 years.

I called Audi and told them about the brakes and that I had read about the recall on here (I never mentioned my letter, was pleading ignorant)

Anyway, I took it in today not really holding out much hope and was happy to return an hour later to find a printout detailing worn drop links, 90% brake disc wear (they are only 2 1/2 years old) and a buggered servo.

the good news....They told me the car was too dangerous to drive and that they would repair the servo and check the brakes under the recall warranty...FREE OF CHARGE...I couldn't believe my ears

The printout had £832 for all the parts listed above, this is without labour, but I am just getting the free warranty work done, will get the other stuff done elsewhere.

I am happy to be an Audi driver once again.

Picking the car up tomorrow, hopefully back to its best again.

1 point I forgot, whilst driving with the said knackered servo, the car went into limp home mode. Couldn't get over 50 mph all the way to work and home. I was told this was nothing to do with the servo by.....wait for it....the receptionist....hahahaha.

Surely it has to be linked...This morning the barkes worked fine and my engine was running as normal as well, on my way to the garage..typicall eh?

Do me a favour love...2 sugars and milk please, leave the diagnostics to the tecchies...

Sorry, I'll probably get sacked for that last comment.