Your thoughts on my discs?
Discussion
I had similar on my 435d with m sport brakes, no vibes on firm braking but anything below 60ish on light braking would cause a vibration in the car.
I changed the disk's / pads on all 4 corners ( they were due ) and problem was still there. I then got a dti gauge to check for any run out of the disks and hubs. They were all in spec.
It ended up being the front control arms, there was a bit of movement in the bushing, and after changing the arms the brakes returned to normal..
I changed the disk's / pads on all 4 corners ( they were due ) and problem was still there. I then got a dti gauge to check for any run out of the disks and hubs. They were all in spec.
It ended up being the front control arms, there was a bit of movement in the bushing, and after changing the arms the brakes returned to normal..
asfault said:
Car bmw 335d. Disc and pads have done 25k
Heavy uncomfortable juddering through the wheel and shakes the whole car from the front. When breaking moderately at 60
Doesn't do it on really really heavy braking.
Well known issues are, as already said above; front thrust arms failing/failed (either the ball joint or the large bush at the other end); hard to see sometimes until removed and the ball joint can be flopping about!Heavy uncomfortable juddering through the wheel and shakes the whole car from the front. When breaking moderately at 60
Doesn't do it on really really heavy braking.
It's generally the suspension arms that cause steering wheel / car wobbles at speed and under braking; rarely the discs
Discs don't warp; but they do get pad deposits on them, usually you can clear them with some hard but safe braking
Try that first to rule out the brakes themselves (unless the calipers are sticking) and see how you get on...
Looks llike you've got pad imprint (pad transfer) which can definitely induced brake judder.
Had the front & rear rotors on my M5 replaced this week having had brake judder for quite some time:
(Above) Front rotor
(Above Rear rotor
On my car the pad imprint is slightly worse on the inside faces of the rotors due to the design of caliper. Probably happened on my car after a trip across the Alps to Italy a year or two ago. Sustained hard braking in descent followed by holding the car on the footbrake at a traffic light or something in a nearby village.
No amount of "rebedding the brakes" with a series of hard stops would shift the cementite that had formed.
Another ususal suspect, as had already been alluded to, are the front control arms. The nightmare scenario is having pad imprint + a 'soft' failure of the control arms. (Soft failure meaning the bush on the control arm will pass the usual pry bar test but be sufficiently degraded to no longer fully absorb vibration from braking and steering loads.)
Had the front & rear rotors on my M5 replaced this week having had brake judder for quite some time:
(Above) Front rotor
(Above Rear rotor
On my car the pad imprint is slightly worse on the inside faces of the rotors due to the design of caliper. Probably happened on my car after a trip across the Alps to Italy a year or two ago. Sustained hard braking in descent followed by holding the car on the footbrake at a traffic light or something in a nearby village.
No amount of "rebedding the brakes" with a series of hard stops would shift the cementite that had formed.
Another ususal suspect, as had already been alluded to, are the front control arms. The nightmare scenario is having pad imprint + a 'soft' failure of the control arms. (Soft failure meaning the bush on the control arm will pass the usual pry bar test but be sufficiently degraded to no longer fully absorb vibration from braking and steering loads.)
asfault said:
How big/ expensive a job is the control arms to replace?
Not massive; get Moog parts from your local motorfactors (or order Lemforder/TRW - they're OEM) from the likes of Autodoc (they'll take about 7-14 days to arrive) and then a couple of hours labour at a garage or a few hours DIY.Moog are very good parts with very good warranty; I highly recommend them
You'll need tracking and alignment after though
Brake pad deposits and bedding in are a tricky question with no "one answer fits all".
If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
Panamax said:
Brake pad deposits and bedding in are a tricky question with no "one answer fits all".
If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
I always get the brembos from autodoc which I think are the most expensive.If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
asfault said:
Panamax said:
Brake pad deposits and bedding in are a tricky question with no "one answer fits all".
If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
I always get the brembos from autodoc which I think are the most expensive.If uneven pad deposition has been caused by excessive heating of the brakes - which might be as little as one hard stop from motorway speed - further hard braking is likely to make things worse, not better. You're better to just "drive normally" and let things gradually return to normal. There's a good explanation on this link,
https://centricparts.com/media/wysiwyg/technical-b...
Pad marks on a disc are similarly best cleaned up by normal driving.
There's a lot to be said for OEM discs and pads to keep your brakes working as the manufacturer intended.
However, they're not OEM - ATE, Jurid, Textar and TRW make BMWs discs - not sure which 335D BMW you have but they'll probably be either TRW or ATE
I'd highly recommend the ATE 2 piece discs and their Ceramic pads from Autodoc; or go OEM BMW discs and pads via Cotswolds BMW or Douglas Park (not that much more than the ATE parts via Autodoc)
I had the same issue on a 420d, discs looked almost new when I got it but developed a judder exactly as you described.
Turns out the discs were nearly new but had been fitted on hubs that were baked in crap and were not seated properly.
Had to renew as the discs were warped,no issues since then.
Turns out the discs were nearly new but had been fitted on hubs that were baked in crap and were not seated properly.
Had to renew as the discs were warped,no issues since then.
I had this last year, I knew it wasn't the arms as they had already been changed. It looks very like pad transfer, the inner face will be worse.
I tried to clear it with last of the late breakers breaking, made no difference.
Do you clean the wheels and not move the car afterwards? It's a light skim (if enough left) or new disc/pads time.
I've not used them, but they can be done in situ - https://skimmydiscs.co.uk/
I tried to clear it with last of the late breakers breaking, made no difference.
Do you clean the wheels and not move the car afterwards? It's a light skim (if enough left) or new disc/pads time.
I've not used them, but they can be done in situ - https://skimmydiscs.co.uk/
I always have this issue on my 325ti during the winter months. Sits outside on the driveway with all the inclement weather and doesn’t get driven that much. Looks like the metallic parts of the pad are corroding when they are sat next to the disc for a period of time. Does it get parked up for long periods?
I ended up just replacing the discs in the end as they were so cheap through autodoc (£60/pair for Brembos). I used to get them skimmed on the car, but they now want £100 per axle!
I ended up just replacing the discs in the end as they were so cheap through autodoc (£60/pair for Brembos). I used to get them skimmed on the car, but they now want £100 per axle!
Edited by SimonK2486 on Monday 19th August 21:19
bigdom said:
I had this last year, I knew it wasn't the arms as they had already been changed. It looks very like pad transfer, the inner face will be worse.
I tried to clear it with last of the late breakers breaking, made no difference.
Do you clean the wheels and not move the car afterwards? It's a light skim (if enough left) or new disc/pads time.
I've not used them, but they can be done in situ - https://skimmydiscs.co.uk/
Yeha I'd heard and tried the heavy braking technique but never worked. Could be from sitting but it's never more than 3 days. Defo will go a quick drive after a wash in future but skimming price looks close to new discs price and with pads needed either way the cost difference will be negligible.I tried to clear it with last of the late breakers breaking, made no difference.
Do you clean the wheels and not move the car afterwards? It's a light skim (if enough left) or new disc/pads time.
I've not used them, but they can be done in situ - https://skimmydiscs.co.uk/
My front discs have never been right either. Loads of corrosion on the lower lip of the discs, and the car only had 13k miles on it when I got it. I reckon that it lived its life on a racetrack before I had it in fairness!(F82 M4).
It had definitely lived a hard life, because I've never seen discs in such a poor state for something relatively new versus other cars that I've owned.
I bought it in covid lockdown times, so I never got the chance to give it a once over.
It had definitely lived a hard life, because I've never seen discs in such a poor state for something relatively new versus other cars that I've owned.
I bought it in covid lockdown times, so I never got the chance to give it a once over.
Discs can and do warp. Genuine ones generally don't as the steel quality is superior, but aftermarket ones do. You only have to jack the front up and spin a wheel to feel the horrendous run-out grabbing on the pads. Yes, AutoDoc supplied ATE discs, I'm pointing at you!
The other arms (aka lower) are also £160ish each but you do need an alignment after replacing those. It's usually the thrust arms that go first.
Personally I'd do all 4 as preventative maintenance and enjoy proper steering and braking again.
asfault said:
How big/ expensive a job is the control arms to replace?
The arms are £160ish each for genuine. Thrust (aka upper) arms are 40 mins a corner and no alignment needed afterwards. Dead easy job DIY. The bolts and nuts are one time use, so factor those into the parts list.The other arms (aka lower) are also £160ish each but you do need an alignment after replacing those. It's usually the thrust arms that go first.
Personally I'd do all 4 as preventative maintenance and enjoy proper steering and braking again.
rottenegg said:
Discs can and do warp. Genuine ones generally don't as the steel quality is superior, but aftermarket ones do. You only have to jack the front up and spin a wheel to feel the horrendous run-out grabbing on the pads. Yes, AutoDoc supplied ATE discs, I'm pointing at you!
Brake discs are cast Iron not steel. Wills2 said:
Brake discs are cast Iron not steel.
You've never spoken to my local dealership, who insist the discs are made of lightweight aluminium or magnesium 
I even tried to correct him by saying that he meant to say that the bell/hat was made from aluminium, but he wouldn't change his answer
But I suppose that just goes to show the service department desk jockeys are not experts.
Gassing Station | BMW General | Top of Page | What's New | My Stuff