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Jim27

Brake judder AGAIN FFS

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I bought my 330ci 3 years ago with 80k on the clock. It had brake judder when I bought it, so I immediately fitted new front disks and pads (Eicher discs and Textae pads) which cured it.

Then the judder came back. I did the bedding in procedure again (a dozen or so hard brakes from 70mph down to 10mph and then back up again, repear x10) and that seemes to cure it. But eventually it returned...

I checked the ARBs in the lollipops and they look solid, no disintegration or collapse whatsoever, no meandering steering and no judder when driving except for under braking.

So, kicking myself for fitting cheapo Eicher discs and Textar pads I changed the discs and pads again (Pagid this time).

Problem solved.

Until 10k later and the brake judder is back again. I redie the bedding in procedure and it massively improved things, getting rid of 90-95% of the judder, but since then it's returned very quickly.

I had discounted ARBs because the problem disappeared when I fitted new discs/pads. I still feel this is an accurate and sensible conclusion.

So I was wondering if I have a sticking caliper. So after a drive I got out and felt each front wheel and the calipers themselves - neither were giving off a lot of heat, and neither one more so than the other.

So I'm stuck. The fact that the symptoms disappeared for a while with new discs & pads leads me to conclude it's definitely something in the braking system. Any ideas??

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I had the exact same symptoms on my e46 and the only thing i didn't replace was wheel hubs.

The car was written off before i had the wheel hubs replaced

was a big saga wasnt it,quite a big thread

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I checked the ARBs in the lollipops and they look solid, no disintegration or collapse whatsoever, no meandering steering and no judder when driving except for under braking.

Thats no a propper diagnosis im afraid Jim, mine 'looked' ok from a visual inspection,& had no real play, however under braking mine was juddering & I replaced the lolipops & it cured it straight away. Mine wasn't wandering either.

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Check your rear brakes as well. I had brake judder pretty bad and would have sworn it was the front. Turned out it was a rear disc. Didn't always do it, either.

Yeah I thought that however the fact that replacing the front disks & pads cured it completely (albeit for about 10k) makes me thing it's front-end, not rear.

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I checked the ARBs in the lollipops and they look solid, no disintegration or collapse whatsoever, no meandering steering and no judder when driving except for under braking.

Thats no a propper diagnosis im afraid Jim, mine 'looked' ok from a visual inspection,& had no real play, however under braking mine was juddering & I replaced the lolipops & it cured it straight away. Mine wasn't wandering either.

Yeah I was thinking that. Just can't understand though how replacing discs & pads would stop the juddering for 10k, and how carrying out the brake bedding in procedure would vastly reduce the judder too.

I might just bite the bullet and poly bush the lollipops and refurb the brake caliper seals too as well as replacing the discs & pads all at the same time. Only thing is I absolutely bloody loathe dealing with brake fluid and having to bleed brakes :(

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I've got Pagid discs and pads all round. Until this latest set, I always swore by Pagid, but now I think their quality has gone down-hill. Firstly, the discs start to rust on the braking surfaces at the first hint of any dampness in the atmosphere. Secondly, and far more annoying, the pads leave a sticky residue on the discs which creates a judder until you burn it off.

OP, when you park-up can you see outlines of the pads around the disc surface??

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A sticky caliper would explain. If it's only slightly sticking, it would heat up the discs and over time, eventually warp them. This would explain why changing the discs cures it but only for a limited time. Having something similar at the moment. Just ordered new pads, discs and a caliper.

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Yep gave it a good scrub with a wire brush but will do it all again lol.

I'm due an oil change in a couple of thousand miles and having just hammered my credit card with professional exam fees, motorbike bits and wheels I'll hang fire until the oil change is due and probably do it all in one go.

Just need to hunt down a DIY guide to brake caliper seals replacement, including bleeding the brakes. And lollipop bush replacement.

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could probably be the pads leaving an uneven pad deposit. When you do the pad bedding in procedure your getting some serious temperature into the pad and disc until the point they start to fade which leaves an even pad deposit on the disc which is good but over time when your braking here and there on your way to the shop etc you remove the pad deposit as the pads and disc are cold then you put some heat in them and add some more pad deposit but not in a controlled way so you have high and low spots.

I would try a more aggressive pad as you obviously like to use your brakes properly and i think its the cheap pad leaving nasty pad deposits on the disc and after 10k you have probably found a s**tty part of the pad made of cheese.

I had Pagid discs and pads alround and to start they was alright but i found them lacking power and had the judder but only when getting them hot, cold they were fine but i put up with it. Just recently fitted Brembo Max discs up front with Pagid pads and found the pads awful! Next to no braking power when you really wanted it and half the pad is missing as they file off the edges so much its just silly so i have now put EBC yellow stuff pads in alround which is a mild form of fast road/ track pad that works from cold and new EBC rear discs + fluid and i was very impressed from the braking in procedure, lots of power, nice consistent pedal, after 15, 70to15 mph stops i had no fade and has left a very nice pad deposit around the disc and so far have been spot on.

Freshly bedded in.

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Edited by R11CH
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Just let me get my head round this for a minute...

The E46 caliper is a sliding caliper, effectively a floating single piston arrangement that relies on it being able to move back and forth smoothly along the slide pins.

When people refer to a "sticking caliper" or "sticking piston" as the cause of brake judder, I've always found it difficult to understand how an underperforming piston would cause judder directly. I had 6-pot calipers on my old Ninja and when half of the pistons seized (crap design) the only symptom was reduced braking strength. I could go so far as to understand judder from a multi-piston arrangement, with say 2 pistons per pad, when one edge of the pad is being pressed onto the disc harder than the other. But not on a single piston set up.

So my conclusion is that by "sticking caliper" people are referring to corrosion on the slide pins, yes? Which then confuses me as to why people then recommend a brake caliper refurb with new seals to cure a "sticking caliper"...? I've seen people say that a refurb cures the judder but I'm now wondering if the only part of the refurb that makes any difference is removing, cleaning and greasing the slide pins.

On that note, what would people recommend for greasing the slide pins? Bog standard copper slip (the bronze coloured stuff), hi temp lithium grease, or anti-sieze copper lubricant (silver coloured stuff)?

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I get no judder or vibration under normal driving and it only occurs under braking.

I've never been able to detect any excess heat coming from either discs or pads after experiencing the brake judder.

I can't detect any "catching" on the brake discs when I spin the wheels (car on axle stands).

When I've previously replaced discs and pads the judder has disappeared completely, but then returned 10,000 or so miles later. Twice.

So I'm putting the car up on axle stands this weekend and will replace the front lower control arm rear bushes (lollipop bushes) with Powerflex jobbies, will remove all calipers, clean and lube the slide pins as well as cleaning and painting all 4 calipers. I'll fit new pads on the front too, and will inspect the rears for any uneven wear but just refit them if they look ok. I'll then go and carry out the brake bedding in procedure (multiple emergency stops down to 10mph from increasing speeds). Do we think (silent prayer) that should finally kill off the dreaded brake judder?

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Have you got a dti gauge? Measure the disc run out. Sticking caliper means either the piston is not moving freely or the slide pins aren't. If you remove that caliper the pins should push through the rubber bits easily, if not clean and grease with some rubber grease. Then push the piston back and press the brake pedal to move it out. If that moves relatively easy then that's not your issue. I've never seen sticky calipers cause judder so would still be looking at disc run out. And you could have easily just over heated the disc at some point in 10000 miles causing them to warp under normal wear

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On ‎09‎/‎09‎/‎2015 at 11:59, Jim27 said:

I get no judder or vibration under normal driving and it only occurs under braking.

 

I've never been able to detect any excess heat coming from either discs or pads after experiencing the brake judder.

 

I can't detect any "catching" on the brake discs when I spin the wheels (car on axle stands).

 

When I've previously replaced discs and pads the judder has disappeared completely, but then returned 10,000 or so miles later. Twice.

 

So I'm putting the car up on axle stands this weekend and will replace the front lower control arm rear bushes (lollipop bushes) with Powerflex jobbies, will remove all calipers, clean and lube the slide pins as well as cleaning and painting all 4 calipers. I'll fit new pads on the front too, and will inspect the rears for any uneven wear but just refit them if they look ok. I'll then go and carry out the brake bedding in procedure (multiple emergency stops down to 10mph from increasing speeds). Do we think (silent prayer) that should finally kill off the dreaded brake judder?

Jim, how was the car after doing all this or have you done something else since to cure the problem?

Both my cars brakes are lightly juddering now. Fitted new discs/pads April last year. Fine until now. 

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8 hours ago, MICK 330 said:

Jim, how was the car after doing all this or have you done something else since to cure the problem?

Both my cars brakes are lightly juddering now. Fitted new discs/pads April last year. Fine until now. 

i had a judder a while ago,changed my front/rear trailing arm bushes,its fine now,the judder was only on high speed braking when it was coming close to stop,say 40 mph..

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