Hi, new to posting - although I have used the site before and found it useful.

I have a problem with the brakes on my 1.4tdi Fabia (2003, AMF 6Y) that I hope someone can shed some light on. I will start with an outline of events:

It started with the front offside binding. Mechanic I know had a look, cleaned them up, and noted that the general condition seemed to be good, although the nearside pad had broken away from the backing plate.. Plenty of meat left on them, but replaced both sides anyway, cleaned them up (also checked rear drums - all OK) and off I went.

Later found that it was still binding - wheel hot as hell and vibrating through steering wheel when braking at speed. Back I went, caliper was stripped, was told slider pins were OK, o/s piston removed and that looked OK too - no scores etc and moving freely inside caliper.

At this point we decided to replace the hose in case that was the cause. Bled brakes up again, road tested, and for a couple of days I thought we'd cracked it, only for the problem to re-appear. Note that both rear drums were (and still are today) fine.

Now, this is the interesting part, so I will try to recall as much detail as I can (this bit was 3 months ago now!). The problem seemed to get worse when the brakes had become warm, so I waited until they had started to bind, and in an attempt to try to suss it out a bit for myself, I jacked up the car only to find that BOTH sides were now binding (although the offside was definitely worse). This didn't seem to be the case initially! I also carried out the usual check to see if the servo was functioning ok by pumping pedal with ignition/engine off, holding foot on pedal and checking that it sinks (almost) to the floor on startup..

Back I went to report this to my mechanic mate who said that due to both sides sticking he could only think that the master cylinder was at fault. So, off I went and bought a new (pattern part) master cylinder. On it went, drive home OK, next morning to drive work OK, but on way home the binding started again -worse this time. Only able to free off by stopping the car, switching off and pumping the pedal before moving off again. No free movement in pedal either, but after they're freed off the pedal has more travel, only to gradually decrease until they start binding again.

At this point the whole thing is driving me to distraction, and I am not sure whether it's caused when the brakes become warm.

By now my mechanic friend is clutching at straws, and as he's going on holiday I decide to get a second opinion from a garage, so I choose a recommended establishment which have a reputation for being straight up and honest. However, due to the nature of cars and garages, this is where it starts to cost me serious money..

I asked the garage to check the whole brake system for their own independent opinion. They eventually crack a bleed nipple (somewhere - not sure where) and reckon up that it's the servo that's at fault. Now, by this point I am pretty desperate and, I guess, rather gullible. Off I go again to buy a new servo (genuine part), and they fit it, convinced that all is well. I am however, told that the old servo was full of oil, and that this was probably caused by the vacuum pump. I am advised that I should replace this at some point to avoid damage to the new servo. Not good news but it was noted.

Off I go again, but a day or two later they are binding again. In my frustration I reached down at the pedal, by now wondering if the cause was something to do with the mechanical link to the pedal. I did succeed in breaking the brake light switch (which I later learnt were defective anyway), and this caused the garage to check and replace the vinyl clip at the back of the pedal. STILL no joy..

This is the final straw. It may or may not be worth noting that the problem does not seem to be so acute at this stage - not sure whether this is just because I have the knack of pumping the pedal automatically at traffic lights etc). Having called the garage again to discuss (having no better ideas), they suggested that I dropped it in when binding so that they could pull the vacuum pipe off the servo and see whether the brakes free up. I am told that there is a release valve in the vac pump, and they wanted to see if this was the cause. Sure enough, as soon as the pipe was dragged off the servo the car rolled backwards. Now, as you might have guessed, this is all new to me so I want to take their opinion, so, off I went and spent some time searching for the part (in an attempt to 'save' a bit of money). New, they are expensive, so I opted for a second hand unit.

On it went yesterday, all OK at first but then driving home today and guess what? Yup, I note the reduced travel in the pedal and lo and behold, both fronts are binding again.

I want to get rid, but I cannot let go AND how the f*** can I sell it like that?Without declaring it I just can't, it's as simple as that.

Sorry for the huge post - I just hope someone can give me some ideas. Thanks

A very sad tale indeed, so sorry for that, but, buying "pattern" parts and secondhand parts might be part of your downfall - though I hope not!

 

The way that I see it, when you request a proper garage to fix your car, it is up to them to be able to justify the parts they use, you just supplying them with parts that might fix things means that they are working under your instruction and only responsible for providing the labour, so no come back. My local VW dealer's workshop even need to see the receipt for any parts provided by me that I've got ordered in by their parts department. I tend to do that when I know what needs replacing, and I can't do it myself, and I know they will not stock the part, just saves the obvious "car off road" for a day or so until the spares arrive at the dealer's.

That is indeed a major tale of woe.

 

My thinking is that this must be something to do with the pedal mechanism, because with or without vacuum applied to the servo, no brake pressure should be generated unless something is opening the valve inside the servo which lets atmospheric pressure into the cabin side of it. As far as I know, movement of the actuator by the leverage of the pedal is the only thing that can open this valve. This assumes that the new servo is not a 'dead out of the box' but I don't think that is an unreasonable assumption as you say it was a genuine part.

 

Perhaps the pedal mechanism has some damage that is causing it to be slightly loaded all the time?

 

Edit: Having read fabdavrav's explanation in post #5 below, I don't believe a word of what I wrote above. So I've crossed it out for you!

My only experience of this sort of problem was years ago and down to maladjustment of the servo master cylinder actuator. Some one had replaced the master cylinder and servo with one from a larger engine without checking the adjustment. I started loosing brake fluid into the servo ( white smoke out of exhaust when braking) and on replacing the master cylinder got binding of brakes. However ,be carefull as it's not possible to adjust the actuator if it's been glued in position. I'd take this as for info only and seek further professional help .

Re the front calliper sticking...............

 

 

This is a common fault as the callipers age................(I'm surprised that your mechanic did not fully solve it first time!).

 

What happens is that the rubber seal between the piston and the calliper body goes hard with age/heat ...........this seal is what retracts the pads away from the disc as it has a built in cam action...................when the seal goes hard the piston does not retract away from the disc and so the pads are still in contact with the disc............then you get heat build up (when you stop to look you can feel the heat ...been there done that)............

 

.........just get a new seal kit and dust skirt................bit fiddly to fit the new dust skirt.........done all four on my car cost about £40 in dealership parts (seals/skirts)................mind you my mates MKIV Golf had the same problem but the dust skirt was split and the piston very rusty and the caliper very badly sticking on so beyond repair so got a new/refurbished OEM caliper.

 

 

If you can jack each wheel up and with the brake released and the car not in gear (neutral) can you freely rotate the wheel??...........does applying the brakes make much difference???................if not then the seals have defo gone on the caliper.

Buy some cheap second hand vrs calipers off eBay, have them refurbished and swap them over. New working brakes which perform better than your current smaller ones

Firstly, thanks to all for your comments, it is very much appreciated.

 

Everyone has a point worthy of note here.

 

I still give thought to the pedal mechanism (Wino & VWD), even though the garage gave this area some attention and reckoned it had been improved (& ruled out I suppose) by a replacement vinyl clip. BUT, the biting/braking point on the pedal does change - one minute there's a few centimeters of travel, then gradually (and then just before the brakes start sticking) it is close to the top (hardly any travel). Might have sod all to do with it of course..

 

As you might have gathered by now, this could take time to resolve because my knowledge is very limited, but if I get a resolution then I WILL re-post. Even though I have never used a forum before, having read countless threads I have discovered that there is nothing more annoying than reading extended accounts of someone's problem only to get to the end and find that they don't tell you how they fixed it! (Maybe some of them didn't..)

 

OK, fabdavrav: This has preyed on me for some time (still does). I had both parties check the calipers, and when mechanic mate dismantled the offside (NB: as far as I am aware, garage didn't dismantle), the seals didn't feel bad (I had a finger in there as well   ). A few other points to consider also:

 

Problem started with one side only, nearside was not sticking initially. Pistons were in very good condition also.

 

When asked the other day about the possibility of the master cylinder being incorrect/faulty, the guy at the garage maintains that because the brakes, when sticking, free up as soon as the vacuum pipe is removed from the servo, in his opinion the issue cannot be with the hydraulics (he also confirmed the same argument for the calipers). 

 

I jacked the car up again the other night when I felt them sticking again, and yes wheels on BOTH fronts were stiff to turn. To free up again, either leave for a few hours or pump the pedal (kind of gently but a good few times over). This sounds ridiculous but it's normally OK on way to work on a morning (20 min journey), but usually occurs on way home - just through normal braking.

 

I am so mixed up in it all at present that I could've missed something here, but I will try to recall other stuff later (it is Friday night after all!). Cheers.

My example was on an older model where the master & servo had been replaced by ones from a higher bhp model. If you've only replaced like for like, I'd tend to go with

fabdavrav's  idea.

I had brake problems at last MOT, on uneven braking, solved by removing calipers , pumping brakes to move piston out and wiping piston with brake fluid to lubricate. But I also found thread problems on one holding bolt, which was also replaced .

OK thanks VWD. It feels better to rule certain things out, and that's now 2 people backing that idea.

All I need now is for someone to make sense of the vacuum argument!

I've changed a couple of servos for this exact fault. Brakes lock on, pop off the vacuum pipe and it then rolls. There is no adjustment to the rod, just needs a new servo.

The opening post says that the OP already had a genuine replacement servo fitted, albeit by an independent.  Are there any obvious ways that it could be damaged during fitting (I can't imagine there are, but I've never fitted one)?  If not, perhaps there's a chance of a warranty replacement on the spare part?

Might have to take the car to a VAG dealer to have faulty new servo diagnosed I guess?

Hi Learner4 - did you ever fix this ????

You said above - " I have discovered that there is nothing more annoying than reading extended accounts of someone's problem only to get to the end and find that they don't tell you how they fixed it! (Maybe some of them didn't..) " - well that's where I am at - your description of symptoms is exactly same as I am experiencing at moment on my Fabia 1 Estate 2001 SDI - no other forum describes it so closely - but you don't tell me the outcome !!!!!

 

Also in case it is the servo on mine - I have been looking into buying one - but the only parts available online seem to be used parts from breakers - none of the big suppliers seem to offer NEW servos. Do I have to go to a Skoda dealers to buy a NEW servo - or are FTE parts available anywhere ????

 

Does anyone have any tips (or links to tips) on how to unlock that clip on the back of the pedal - without having the special tool ???
[Part number / price of new clip ???? in case I break it.]

 

Any help most welcome - to get me out of this frustrating situation - and probably others - as I note 3 people are reading this topic right now !!!

Hello all, sorry to revive an old post...

 

I had pretty much exactly the same problem on my polo, brakes binding when hot, pumping the pedal far as poss 3 times when stopped would release them but when braking slowing down they would bind again!!! So frustrating!!!

 

My car is a few years old now and has done 186k so i knew the brakes needed sorting!! 

 

I had new front calipers, discs, pads, new flexi hoses and new calipers on the rear.....

 

Still the brakes were binding...

 

Had the abs pump changed, thought we'd cracked it then binding again!!!

 

Next step was to change the brake master cylinder to see if that would solve it, but after reading on here about servo and vacuum pumps briefly, I mentioned it to my mechanic....

 

He has changed the pipe which goes from the servo to the vacuum pump and it has finally fixed it!!! 

 

Apparently they have a one way valve in and when tested mine was sticking 9 times out of 10 causing the brakes to bind!!

 

Hope this helps some of you!! 

It's the new shiny black pipe in the photos...