Heres the story, drove down to Cornwall, about 300 miles, on a steep downhill i braked and felt an awful vibration (70mph) did this twice. Then it went away. Could have been the road. Anyway i drove around Cornwall which has lots of hills so had to brake a lot, but didnt hold the pads to the disc when coming to a stop etc.

Anyway a week after getting back driving down the motorway on the way home i braked and noticed the front dip to one side. So i took the brakes apart and had a look, there was a mark in the pad where a stone had been. Anyway took it to get the brakes checked and suspension to make sure it was that (as it did it a few more times, i think!). All was fine. I did notice wear to the inner drivers side front tyre, but not the other? So i had the alignment checked and that side was 1mm out.

I noticed a few days later that when i braked especially from high speeds i could feel a vibration through the brake pedal and steering wheel. I thought it was uneven deposits, so i braked hard for a while and it got a lot better. Now this is where i am at. When braking from 70mph its fine until you get from 40-30mph in which you get a slight vibration through the steering wheel, maybe a little through the brake pedal I'm not 100%. But sometimes its there, others its not. Its really baffling me! I dont feel it when braking hard but that could be because I'm slowing down so fast.

Brakes were changed a year or two ago and have lots of meat left on them and brake fine, even under hard braking. Nothings really changed since.

All suspension is fine as it was checked. Brakes were checked on the machine they use for MOT. Wheel bolts are tight.

It seems like its from the front left but I'm not sure.

I do 30 miles each way every day which is 90% motorway so little braking. I dont thrash the car, infact I'm very gentle on it.

Any ideas anyone?

It will be going in for a service in 3k so was going to ask them if it hasnt sorted itself.

What brand are the disks and pads? Sounds to me like there warped but I would say that is quite unlucky but deffo not worth ruling out!

Especially as they were tested on the mot brake machine which should show bind or imbalance!

Tommy

They are mintex rotors and pads all round. Never had any problems.

I'm with Tommy on this - Suggest that you get the wheels off and check the discs for run-out.

Regards

The thing is. Today they have been fine. Which is baffling me. I'm wondering if braking is amplifing the road.

Its done it today. I was slowing down slowly on the motorway and again on a dual carriageway. Again at 30-40 mph. Its nice and smooth until then in which it feels like it pulsates from one side to the other. I cant feel it under hard braking.

I dont see how it can be anything to do with the brakes as its fine at high speed and under hard braking.

Could it be the abs?

Checked the discs with a dial indicator today. One side had around 1.5mm runout and the other 2.5mm.

Going to order some new discs and pads. Can anyone recommend any?

You pays your money and takes your choice I am afraid.

The problems with discs of unknown quality, is that they can be made from 'green' castings - perfectly OK when they are new, but then with the passage of time, the stresses come out of the cast iron, resulting in distortion.

I have had discs from factors which have been perfectly alright, but there is really no way of telling.

Genuine VW ones will be good, but expect to pay a bit more for them - it ALWAYS pays to check the price of genuine parts before you buy from elsewhere, as often they are very competitive.

This problem of yours does sound a bit odd. Is there any sound when this happens, also, can you feel the brake pedal 'pulsating' - (It was your use of the phrase 'pulsating' that gave me the thought of this) What I am thinking here, is that the ABS may be 'kicking in'.

Regards

I checked the runout and they are out by quite a bit. I can also feel it slightly when braking from high speed.

The discs and pads were Mintex.

The only thing that come to mind is when i was in cornwall i was braking hard as a result of hills. Then there was torrential rain.

Iv been looking ar ferrodo but they are a bit expensive

Ordered some brembro discs and pads for £60

Not bad. I'm running some pagids at the moment but I am not impressed. I'm going back to Ferrodo/VW OEM/Bosch

PoloD.

I was looking at Ferodo but they were expensive

The runout was 0.15 and 0.25mm, i read the scale wrong.

Iv misplaced my manual atm, can somebody tell me the recommended?

Hope that you get a better answer than this, as i don't have a manual covering your model.

The 'generic' run out that I would change (or at least, re-position) discs at would be 0.05 mm to 0.1 mm

So, using that as a 'rule of thumb', yours are well out.

NOTE: you can get run-out, even with new discs, this is why I mention re-positioning, which might involve a rub over the mating faces with some emery cloth.

Regards

Thanks for the reply.

I already have planned to scour the hub face with an abrasive loose wire wheel.

There's no limits mentioned in ElsaWin just a minimum thickness for the discs 18mm for 20mm discs & 16mm for 18mm discs

Replaced the pads and rotors and checked runout after a week or two as the pattern that was on it was throwing it out and got 0.02 and 0.06mm. Turned out to be the tyre, swapped front to back and it went instantly, whod know?...

So... Its back, only very slightly but its still there, i have done about 2000 miles since. Can feel it in the steering wheel when braking lightly from 40-30 again, no major wear to tyres or anything.

Going to get the tracking checked tomorrow. Dont want it to knacker the tyre up again!

Just had someone turn the wheel with the engine off to listen and look for anything (track rods, ball joints etc) but could only hear the steering rack? Lost where to go now....

Could it be that i drive along the M1 every day where there is quite a bit of camber on the road?

Get the wheels balanced if they haven't been recently, i had a similar problem of vibration when braking between 60 and 50, the brakes were all new, the suspension had been rebuilt, i had given up. Then i changed my alloys for freshly refurbed and balanced ones and my vibration went instantly.

Thanks, I'm getting some refurbed anyway. I'm thinking it could still be the rear.

Little update. The vibration came back slowly over 1000 miles after swapping the tyre. I had another look and found the drivers side inner tie rod had gone. Garage replaced both inners and outers for £230 tracked. Touch wood the vibration has gone. It was still there at first so i got the front wheels balanced which made no difference. After driving a few hundred miles it seems to have gone so must have worn the tyres a little more evenly.

Still there. I had the garage that did the work have a quick look, they put it on the brake tester and found the ns front having a variation. The back were fine.

Had the discs skimmed on the car last week. So it cant be the discs still surely!

I'm wondering if its the control arm bushes I fitted. They were febi bilstein so shouldn't be bad quality.

From what I feel its like the car is rocking forwards and back slightly when braking at slow speeds. The vibration is most prominent around 40-30.

Bit stuck on where to go from here.

Any advice is appreciated

Do you have ABS? This fault seems intermittent and could be symptoms ofor a dirty sensor or more likely pickup ring.

The vibration can feel strange if you're unfamiliar with it and it's cheap or free to check and put right.

Apologise if it's been mentioned before I haven't read the whole thread.

I do have abs yes. But surely i would get some sort or error which the service would pick up when they check?

Does this happen when in gear and out of gear, could it be possible its related to the engine/gearbox and not the brakes? you mentioned rocking back and forth which could mean the lower engine/gearbox mount isn't in the best shape, but this is a wild guess?