Steering/brake pedal judder upon braking - BMW F02

[ishaqmir]

Hi everyone

hoping to get some help with this on-going problem, which i've researched into A LOT on the internet but still no luck.

Ok, I bought my BMW 730ld 2011 reg (53k genuine on clock) this April 2016. the brake judder was present at time of sale and the seller said that he had replaced the front discs and pads 01/2016 from local mechanic but with genuine BMW parts. I still bought the car as thought I could spend some money and get it sorted.

So I then took it to my trusted local mechanic and he had a good look and said the front discs and pads needed changing and possibly one calliper just needing some service as may be ceased. He fitted genuine Brembo discs and pads, total cost me like £550!!

All the judder had gone away after they were fitted, so led me to believe it was indeed the front discs and pads.

Just one month later (500-1000 miles) the same problem returned. This time i took it to BMW dealer for a diagnostic and they said the front control arms needed replacing as they were vibrating on the discs and causing premature wear/tear.

So i paid £600 just for the pair of control arms from BMW and my local mechanic fitted them and also replaced the Bremdo discs and pads under warranty. Problem went away again and car drove immaculately.

Until.....another 6 weeks (500-1000 miles) and EXACT same problem AGAIN!!! So took it to my local mechanic again and he has replaced the front brembo discs and pads again under warranty but also did a thorough check on other parts and said everything was fine. He put the car on the MOT wheel rollers too and checked the front brakes and said callipers were working perfectly and that I shouldn't change them.

I picked up the car yesterday and is driving fine so far (only covered 70 miles), but i'm dreading the same problem returning after a few weeks.

My local mechanic has told me to just brake gently for 500 miles, which I have always done after each replacement anyway. He said if the problem returns again he will either send my car to a friend who is technician at BMW or just try a completely different brand of discs/pads like ATEC? (i think that was the name he used).

Yesterday after driving for about 30 mins with just gentle braking, I got out and touched the front discs to see if one was hotter than the other. Neither of them were 'hot', they were just 'warm' and the driver side seemed to be just slightly warmer. I ran this test again later on and found the same, discs just warm, with driver side slightly warmer.


any help would be much appreciated as the car drives beautifully otherwise but let down by the brakes.

Thanks

Read more: http://carmechanics.proboards.com/thread/3779/steering-brake-pedal-judder-braking#ixzz4JO1OQj2b

 

[Burnerman]

Has anyone checked the condition of the rear brakes for you? There's more than just a coincidence here!
I'd also want to see a run out test done on the front hubs, just in case there's a warping issue with them......I'd also hope that had been done by now!
John

 

[ishaqmir]

Many thanks for the reply.

My mechanic inspected the rear discs and pads said they were ok, although pads will need to be changed soon, they are a little less than 50% thickness. What I did find with the rears is that when hand brake applied and I get out of car I can for a moment hear the rear discs creak as though pads not pressing on them hard enough.

But how can the rears cause the fronts to warp?

Thanks

 

[ishaqmir]

Also, I don't think they've done a run out test on the front hubs, don't even think BMW dealer did that as they got the diagnosis wrong anyway.

Who could I go to in Birmingham/Solihull?

Also, I had front alloys balanced, the tyre place said they couldn't really notice any significant buckling of the wheels. They are 20" alloys. If I don't press the brake, no vibration through steering even at high speed. Does this mean wheels are ok?

Thanks

 

[Burnerman]

Any problems with the rear brakes could give a juddering pedal, but of course the steering wouldn't be affected by this. Don't be worried by the odd creak, either.
Your wheels sound true, so therefore your problem is either with the discs and pads, or with the hubs they are bolted to. If it was mine, I'd test for hub run out with a dial indicator, and then test again with the disc in place.
Brembo are supposed to be world leaders with brakes so I'd have to doubt any problems there.....especially as they have been replaced anyway!
Personally I use ADL Blueprint parts and find them excellent.
John

 

[ishaqmir]

Ok I just had a chat with a reputable BMW independent in Solihull and he is saying that he had a similar case a few years back with an M5, everything was replaced, callipers, hubs, discs pads control arms etc but problem kept coming back. He said the problem was his refurbished front alloy wheels that were not powder coated correctly and heat was transferring to the discs.

Now, the seller I bought the car from did refurbish all the alloys and the fronts look as though it wasn't a good job as the powder coat is cracking and chipping/corroding around the centre caps on both front wheels.

Any advice? But i guess first thing is getting those hubs checked for run out...

 

[Burnerman]

Out of my depth here. ....for sure out of balance or true wheels will certainly cause a shudder through the steering wheel but it would have to be pretty major to affect the braking as well!
Try swapping the rims front to back and see what happens.
John

 

[TargetDummy]

I had a similar problem with a 2005 325i. I changed discs, pads and hubs. Made no difference. It just happened that the tyres needed replacing a few weeks later and this cured it completely. Weird I know, but it worked.

 

[JohnD]

And this was braking-related judder?

 

[Burnerman]

Certainly I've experienced oval tyres before, so that's a possibility!
I wonder if the 20" alloys are the original fitting......the tyre profile must be extremely low, I guess. I'd assume that they would be a decent make too, being a 7 series.
John

 

[ishaqmir]

Hi yes, they are the factory fitted 20" 303m alloys with Pirelli p zero run flats. I had changed the rears just a few months ago so they are brand new more or less. But the fronts have got to be many years old as the rubber has plenty of cracks along the tread, but no signs of uneven wear at all on any of the fronts. I was contemplating changing the fronts, but they are £236 a shot! Lol do you think I should splash out on them? They have about 4-5mm remaining.

Target dummy can you please confirm exact symptoms you were getting? Each time I get the pads and discs changed they are fine for about 1000 miles, then the pedal and steering judder only when braking. Also, brake power no longer constant when pedal pressed, I.e. As though discs are warped giving a pulsating brake power.

Thanks

 

[DaveHerns]

Hubs not being cleaned before discs fitted ? I can't see powder coating being a problem with heat transfer , surely it's the air flow that cools the discs?

 

[TargetDummy]

My symptoms can best be described as a judder or pulsating feeling on both the brake pedal (when braking) and on the steering wheel when cornering. Speed didn't seem to matter but if I had to differentiate, I'd say it was more noticeable at lower speeds.

Like I said, I changed the discs, pads and hubs on the front which had no effect but new front tyres completely cured it. If you don't want to buy new tyres yet, could you borrow some front wheels/tyres just to see if it makes a difference?

 

[ishaqmir]

Thanks Target Dummy, my symptoms do sound similar. I don't get any vibrations at any speed unless I brake. But if I turn the steering a little to left or right I do sometimes get a pulsating feeling through the steering. Also, with brand new discs and pads even after just a few miles, I can feel a very faint pulsating in the pedal, as though I'm feeling the road surface. This is less noticeable on smoother Tarmac

 

[TargetDummy]

I know it's not going to be cheap with those big wheels, but I'd get some new tyres anyway, given your description of the ones on it now, or at least swap front and rears and see what the result is