Warped discs?

[oreA]

So what I thought I'd experienced as warped discs previously was just a speed associated vibration through the brake pedal. But shortly into a track day at Combe yesterday I was getting a drumming noise and vibration through the pedal on braking, again speed dependant, but I was surprised that the noise it made was more noticeable than the rhythmical vibration feeling through the pedal. I can upload a video of it later....

Is there a clever way to check the runout on the discs with everyday tools (like a ruler or summat :tonguewink? It would be good to make sure it's a disc problem I have before investing in new then finding out it's something else at fault, like a wheel bearing maybe?

Thanks :up:.

 

[oreA]

Said video...

 

[JB21]

Brake discs need serious heat to warp, could just be your pads with crap on them. To check for run out you'll need a DTI gauge, I got one from Amazon for £20. Pull your pads and see the state of the surfaces before anything, then check ARB bushes, steering rack bushes, tie rod ends and ball joints for play, suspension, top mounts, uneven tyre wear etc. As these can all cause vibration under braking. I'm currently experiencing it on my Mondeo and still can't pin point it, really feckin annoying as I've checked all the above, think mine could be the steering rack itself.

Wheel bearings tend to be speed related and can be checked by rocking the wheel whilst of the ground and spinning it listening for grinding.

http://www.ebay.co.uk/itm/like/1711...3D710-134428-41853-0%26rvr_id%3D1177670104330

 

[imprezaworks]

Think I'm going deaf as I can't hear much. Only on my phone though.

 

[oreA]

Brake discs need serious heat to warp, could just be your pads with crap on them. To check for run out you'll need a DTI gauge, I got one from Amazon for £20. Pull your pads and see the state of the surfaces before anything, then check ARB bushes, steering rack bushes, tie rod ends and ball joints for play, suspension, top mounts, uneven tyre wear etc. As these can all cause vibration under braking. I'm currently experiencing it on my Mondeo and still can't pin point it, really feckin annoying as I've checked all the above, think mine could be the steering rack itself.

Wheel bearings tend to be speed related and can be checked by rocking the wheel whilst of the ground and spinning it listening for grinding.

That's a good price for the gauge, I like that! I'll check the other stuff before investing.
Can most of these bushes be checked myself (mechanically minded, but inexperienced)? I'll do a search of course.
Top mounts were newly refurbished KTR solid versions, I could always go back to standard to rule them out. Uneven tyre wear I can probably dismiss because I had the same issue with different wheels/tyres on same day.
I noticed the edges of the DS2500 pads were beginning to crumble, so maybe it could be them, I have some spare pads I can whack on and try.

Thanks for the reply :up:.

 

[oreA]

Think I'm going deaf as I can't hear much. Only on my phone though.

Its a low pitched rumble/drumming noise, a phone may not pick it up :wink:. I can' hear it on my phone either






but I am a bit deaf too :smile:.

 

[bloke]

look for a slightly rusty pad shaped bit on your discs :wink:

 

[oreA]

look for a slightly rusty pad shaped bit on your discs :wink:

If this is the case, can I clean up the discs (if so, how?) and pop new pads on?

:up:

 

[JB21]

Wire brush or sand paper, but if on track you would have smoothed them over braking hard.

 

[oreA]

So just to tidy up this thread......

Because the DS2500s were fubar'd I swapped them for some cheapo pads to see if that made a difference and the rumbling/vibration was much improved, but still there a bit. So I fitted new Brembo HC discs & Mintex M1155 pads and everything was perfect. So I think I had a combination of warped discs & trashed pads.

The Brembo/Mintex combo performed admirably at Combe last week, and (to an non-hero track goer) the Mintex were as good as the Ferodos and nearly half the price. And will hopefully last longer!

I'm convinced leaving the DS2500s out in the moisture ruined them, so I've taken the M1155s off the car for dry storage. Bit OTT maybe, but they aren't cheap!

 

[car.crash]

A dti gauge is very cheap and will tell you if they are within tolerance.

 

[oreA]

A dti gauge is very cheap and will tell you if they are within tolerance.

@JB21 linked to one on eBay for £20, and I very nearly bought it, but at £45 for new discs I thought at the very worst I'd end up with a spare set, so wigged out on the gauge 😅. It would be nice to have one though :up:.

 

[car.crash]

You can get the gauge and magnetic base for under £15 posted. Or just lob the discs and replace if they are cheap enough.

 

[JB21]

Just to update my comments above I actually had warped discs on my ST, I thought they couldn't be as they were new but it seems a doing of my own by getting them hot and leaving my foot on the brake whilst stationary warped the shite out of them.

 

[oreA]

Just to update my comments above I actually had warped discs on my ST, I thought they couldn't be as they were new but it seems a doing of my own by getting them hot and leaving my foot on the brake whilst stationary warped the shite out of them.

TBH you had me worried that my problem was going to be something more troublesome to sort 😅, glad it all worked out though :up:. Were your ST discs as much of a bargain as the Clio ones?

 

[JB21]

TBH you had me worried that my problem was going to be something more troublesome to sort 😅, glad it all worked out though :up:. Were your ST discs as much of a bargain as the Clio ones?

Double the price mate at £90. Also threw the parts cannon at it before that, track rods, tie rods, new pads, numerous alignments etc.

I read so many forums saying "you can't warp modern discs" and I'd never had an issue with the HC's on the Clio so fully ruled it out, even the DTI test came back within tolerance. Turns out the inside of the disc was the issue as @bloke mentioned.

 

[charltjr]

I had the same sort of issue on both my Clios with DS2500s, as far as I've been able to find out they're very bad for leaving pad deposits on the discs if they're not very carefully bedded in.

Thankfully no such issues on the M3 with the 2500s, at least not so far.

 

[Chrisgti6]

http://skimmydiscs.co.uk/