Steering/brake pedal judder upon braking - BMW F02
- Thread starter ishaqmir
- Start date
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It certainly is a curious one.....new wishbones have been fitted, and two sets of Brembo discs and pads under warranty. Surely no one would do that without giving the thing a good check over!
The tracking fault should centralise at the steering wheel and show tyre wear obviously enough, you would think.
John
The tracking fault should centralise at the steering wheel and show tyre wear obviously enough, you would think.
John
Makes you wonder why someone with such a nice car that has full dealer history would let this problem persist.
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Welcome back Mr. M! Long time no see.
John
John
Good as gold mate, escaped to Ibiza for a sunny week
John
John
Many thanks everyone for the help. An update:
I had used Kwik fit mobile to supply and fit the new Pirelli run flat Tyres. Got lots of vibration after they fitted the front ones last week. I then took the car to another tyre place whom I've used in the past and they found all 4 wheels out of balance. Anyways, I got the passenger front wheel changed too as it had a very slight buckle (common in BMW 20" rims) and then all 4 wheels balanced. Now the constant vibrations have gone although I can feel a tiny bit of wobble/pulsation in the steering if I'm being fussy. So I'm thinking of taking it to a garage that uses Hunter Road Force Balancing and also get the Hunter Hawk Eye 4 wheel alignment done.
Now over to the brakes issue. It's been 500+ miles and pulsation beginning in brake pedal just as in the past. Reading on the net it really does seem now that it's hub runout, which appears to be quite common. It progressively is thinning the disc unevenly and then after about 2000 miles the amount of juddering reaches its peak and no longer gets any worse. I'm assuming this is when the hub runout has fully transferred it's shape to the disc.
Now I've been looking into disc skimming, even BMW and Porsche do it themselves as a service. Would it be worth doing that after at 2-3k miles once jusdering has reached its maximum? They do the skimming with the discs still on the car so that it can zero the effect of hub runout. I can then immediately get just the pads changed under warranty.
I'm now quite confident it's not warped discs or faulty calipers as after every journey the discs are comfortable enough to touch and sometimes the left is warmer, sometimes the right, and sometimes feels they are equally warm.
Now will it be worth going down the skimming route in 2 months or just go all out, pay another garage who knows their stuff about hub run out and get them to check it out? Is there any benefit of paying all that money to replace hubs rather than disc skimming?
Thanks
I had used Kwik fit mobile to supply and fit the new Pirelli run flat Tyres. Got lots of vibration after they fitted the front ones last week. I then took the car to another tyre place whom I've used in the past and they found all 4 wheels out of balance. Anyways, I got the passenger front wheel changed too as it had a very slight buckle (common in BMW 20" rims) and then all 4 wheels balanced. Now the constant vibrations have gone although I can feel a tiny bit of wobble/pulsation in the steering if I'm being fussy. So I'm thinking of taking it to a garage that uses Hunter Road Force Balancing and also get the Hunter Hawk Eye 4 wheel alignment done.
Now over to the brakes issue. It's been 500+ miles and pulsation beginning in brake pedal just as in the past. Reading on the net it really does seem now that it's hub runout, which appears to be quite common. It progressively is thinning the disc unevenly and then after about 2000 miles the amount of juddering reaches its peak and no longer gets any worse. I'm assuming this is when the hub runout has fully transferred it's shape to the disc.
Now I've been looking into disc skimming, even BMW and Porsche do it themselves as a service. Would it be worth doing that after at 2-3k miles once jusdering has reached its maximum? They do the skimming with the discs still on the car so that it can zero the effect of hub runout. I can then immediately get just the pads changed under warranty.
I'm now quite confident it's not warped discs or faulty calipers as after every journey the discs are comfortable enough to touch and sometimes the left is warmer, sometimes the right, and sometimes feels they are equally warm.
Now will it be worth going down the skimming route in 2 months or just go all out, pay another garage who knows their stuff about hub run out and get them to check it out? Is there any benefit of paying all that money to replace hubs rather than disc skimming?
Thanks
Ye gods you must be demented (and broke) by now!
If it was mine, it's back again to the dial indicator......I'd check that the bearings were spinning smoothly without play, and then I'd test the hub for run out, and then again with the disc fitted.
I've heard of disc skimming on the car but that's way out of my league I'm afraid!
John
If it was mine, it's back again to the dial indicator......I'd check that the bearings were spinning smoothly without play, and then I'd test the hub for run out, and then again with the disc fitted.
I've heard of disc skimming on the car but that's way out of my league I'm afraid!
John
Hub run out on so-called quality german cars? Amazing. I've never had that on French cars which are supposed to be rubbish. Skimming discs in situ to correct hub run out seems to me to be a bodge. You're further thinning discs which have already worn unevenly. Are you sure the run out is not caused by discs being fitted without cleaning the mating surface on the hub and leaving the rust etc ?
Doesn't surprise me Kwik Fit can't balance wheels properly.
I hope the rest of this car justifies the aggravation it's caused so far.
Doesn't surprise me Kwik Fit can't balance wheels properly.
I hope the rest of this car justifies the aggravation it's caused so far.
I've mentioned it before, but don't forget the rear discs need the same check!
John
John
Have you checked the track rod ends? A worn track rod end can give the symptoms you're talking about. Also check the inner balljoints on the steering rack, check that the rack mountings themselves are not loose and maybe check the strut TOP bearings?
I don't think I've ever seen a truly "warped" disc, but I HAVE seen plenty of cars that exhibit symptoms "like" a warped disc and it's usually down to poor bedding-in procedure of a new set of brake pads. It results in a bit of pad material being deposited on the disc surface. Every time that "patch" passes between the pads as the disc rotates, it "grabs" a bit (the result feels like a "warped" disc). Some good articles on it here:
http://www.mossmotors.com/SiteGraphics/Pages/brake_discs.html
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths
I don't think I've ever seen a truly "warped" disc, but I HAVE seen plenty of cars that exhibit symptoms "like" a warped disc and it's usually down to poor bedding-in procedure of a new set of brake pads. It results in a bit of pad material being deposited on the disc surface. Every time that "patch" passes between the pads as the disc rotates, it "grabs" a bit (the result feels like a "warped" disc). Some good articles on it here:
http://www.mossmotors.com/SiteGraphics/Pages/brake_discs.html
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths
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