M5 (e39 / 2001) Brake Judder

M5 (e39 / 2001) Brake Judder

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Discussion

Thor-M5

Original Poster:

4 posts

208 months

Sunday 11th June 2023
quotequote all
Has anyone had an issue with brake judder, it is felt through the brake pedal.
I have changed the rotors & pads a couple of times for genuine BMW parts but the judder returns after 500 to 1000 miles.
Any help or advice would be really welcome.

technicalfoamboy

142 posts

111 months

Sunday 11th June 2023
quotequote all
Thor-M5 said:
Has anyone had an issue with brake judder, it is felt through the brake pedal.
I have changed the rotors & pads a couple of times for genuine BMW parts but the judder returns after 500 to 1000 miles.
Any help or advice would be really welcome.
https://www.pistonheads.com/gassing/topic.asp?h=0&f=&t=2011971

In my experience you'll need to get the brake discs skimmed

https://www.youtube.com/watch?v=aszLDrz51So

HTH

Thor-M5

Original Poster:

4 posts

208 months

Monday 12th June 2023
quotequote all
Thanks but I have already completed all the above in the first video and still the same juddering.

Why would the discs need skimming if they were brand new 500 miles ago?

Also it has happen on 2 brand new sets of discs & pads.

rassi

2,483 posts

258 months

Monday 12th June 2023
quotequote all
How are the front suspension bushes? And after a spirited drive, is one of the wheels hotter than the others, which might indicate a sticking caliper?

Depthhoar

680 posts

135 months

Monday 12th June 2023
quotequote all
Common problem. many have tried chasing it down and failed to eliminate it completely. There are countless posts on M5board about it. Here's a sample of causes, in no particular order:-

Brake pad transfer
One of many ball joints on the front suspension arms and steering tie rods.
Wheel bearing.
Partially seized brake caliper.
Paint/powder coating on recently refinished wheels adhering to the wheel hub
Excessive run-out on a worn brake disc.
Warped (from new) brake disc. Rare, I would say.

Wear in one or more of the suspension/steering parts on the E39 can, in combination, bring about brake judder - or steering shudder at certain speeds that's not related to the braking. Replacing one part can seem to resolve the problem only for it to return quite soon afterwards once the new part starts to wear just a little. These cars are now at least 20 years old and - if not done already - would benefit from a complete overhaul of all the suspension parts.

As the saying goes, you've got to pay if you want to play.

Thor-M5

Original Poster:

4 posts

208 months

Monday 12th June 2023
quotequote all
Have had all the front suspension completely checked when the last set of discs and pads were replaced, the mechanic at the BMW specialist said all was very good and nothing need changing.

Also something I had forgotten that I have had the front hubs and bearings both replaced when the last discs and pads were replaced.

The BMW Specialist is a stumped and can only suggest replacing them with a difference manufacture than genuine BMW.

The issue I have with that it is not cheap and it might not cure the issue.

Not that I can notice but will check next time, the callipers were checked when the last discs and pads were replaced.

julian64

14,317 posts

261 months

Monday 12th June 2023
quotequote all
Yep I had this on my old e39 M5

In my case it was caused by a tight fit and small lip inside the disc which stopped it sitting on the hub straight. No matter how hard you did up the wheel bolts the disc didn't sit on the hub true.

They were BMW OEM discs.

It was sorted by by either taking a mm of the hub diameter or by milling out the lip fron inside the disc. I chose the latter not to affect a more difficult to replace part.

I think if you have wheels which are in balance according to the tyre fitter (and that you've actually seen that yourself) I would go there next.

Depthhoar

680 posts

135 months

Monday 12th June 2023
quotequote all
The various ball joints on the suspension arms often show as worn on the pry bar test but can still be worn enough to exhibit judder, so it's entirely possible you may have one (or more) ball joints worn enough to induce judder.

Not sure I agree with your specialist about BMW parts. More often than not it's the aftermarket parts that are a bit (or a lot) crap.

I feel your pain. Had this issue after a complete front suspension overhaul only for it to return after a trip in the car to the Alps. Eventually found it to be pad transfer. Must have happened after repeated braking coming down one particular set of alpine switchbacks and then, shortly afterward, holding the car on the foot brake at a set of traffic lights in a village.

MikeM6

5,229 posts

109 months

Monday 12th June 2023
quotequote all
I had a persistent brake judder, turned out to be the alloys having been painted on the mating surface and causing the discs to warp (I didn't believe this either until I looked into it). Had it sorted and new discs mean it's now no longer juddering.

julian64

14,317 posts

261 months

Tuesday 13th June 2023
quotequote all
MikeM6 said:
I had a persistent brake judder, turned out to be the alloys having been painted on the mating surface and causing the discs to warp (I didn't believe this either until I looked into it). Had it sorted and new discs mean it's now no longer juddering.
I think that will be the same as my problem. Any small amount of material on the mating surface will misalign the disc from the hub and therefore judder.

Constant heat cycles with judder will eventually warp the disc

DVandrews

1,325 posts

290 months

Tuesday 13th June 2023
quotequote all
MikeM6 said:
I had a persistent brake judder, turned out to be the alloys having been painted on the mating surface and causing the discs to warp (I didn't believe this either until I looked into it). Had it sorted and new discs mean it's now no longer juddering.
This ^^^^ times 100 ; exactly the same problem on my E39 M5, had the disks skimmed on the car and the paint sanded off. Problem permanently solved.

Thor-M5

Original Poster:

4 posts

208 months

Thursday 15th June 2023
quotequote all
Thanks to everyone for their advice.
I going to get all the front suspension and steering bushes checked again.
I will also check to see if there is a small lip inside the disc if there is get it removed.
Next, I will get the mating surfaces of the wheels cleaned/sanded and then the discs skimmed on the car.
Hopefully, that should fix the problem.
Thanks again

LankyMcTally

316 posts

104 months

Thursday 15th June 2023
quotequote all
Add checking your brake callipers to that list. Often subtle but a sticking piston can cause your symptoms. One wheel warmer than the other after a run can be a tell, as is a greater buildup of brake dust on the side responsible.

I’ve used Bigg Red to purchase refurbished callipers on an exchange basis in the past to eradicate just the problem that you have now.

Megaflow

9,929 posts

232 months

Thursday 15th June 2023
quotequote all
technicalfoamboy said:
What he said.

Honda had all sorts of issues with this in the early 2000’s. Replacing the discs never solved the problem, but having the discs skimmed on the car always fixed it.

FYI, normally they don’t warp, as in look like a popadom, it is generally a variation in thickness that is causing the problem.

julian64

14,317 posts

261 months

Friday 16th June 2023
quotequote all
IMHO don't get the discs skimmed, its a waste of money

You either

1) fix the problem and get a new set of discs to put the car back to square one
2) leave the problem there and have someone skim your current discs in situ

After a while of the discs sitting abnormally on the hub the disc will be warped by the action of the judder. If its not been long you may get away with simply fixing the problem. If they have been there a while the judder by itself will have warped the discs.
The cost of the skim is probably only on a par with a set of new discs anyway.

sorting the problem, and then skimming the discs, will simply leave you with a bigger bill, for what will end up being a narrower set of discs.

RichardM5

1,773 posts

143 months

Friday 16th June 2023
quotequote all
I had this on my E39 M5. Several sets of disks cured it for a while, but it always came back.

I finally tracked it down to being due to a set of traffic lights near home at the end of a long straight where you are are stopped facing down hill. The 'natural' behaviour is to stop at the lights and keep your foot and the brake, this causes pad transfer and then judder. The solution was to never, under any circumstances, be stationary with your foot on the brake, always use the hand brake. The combination of the pad material and disks just makes them very prone to pad transfer.