Knackered brake disc?

Concrete · 27 Mar 2012 at 13:40

TRNC said:
What???

1 tiny score mark and you lot are condemning the discs to the bin?? Seriously people, there is nothing wrong with them!

Agree, if you want to be on the safe side, you can get them skimmed, both disks should cost about 50 quid combined, don't take them off the car, a good garage should have a machine that does them in place.

Simon · 27 Mar 2012 at 13:50

I cracked an EBC drilled disk, was only from braking hard on a motorway too. No track involved, ironically it was on the way to my first track day in the S2000.

Simon · 27 Mar 2012 at 13:52

Concrete said:
Agree, if you want to be on the safe side, you can get them skimmed, both disks should cost about 50 quid combined, don't take them off the car, a good garage should have a machine that does them in place.

Skimming won't replace the metal that has been removed to cause the lip though.

I'd have a look, free up the calipers and pads in the caliper carriers then give them some hard use to clean up. However I would check the minimum disk width before bothering with that.

You will have to do all the above if you change the disks anyway. Brakes International do cheap plain disks which are more than up to the job.

Firestar_3x · 27 Mar 2012 at 14:45

HummuH1 said:
Interesting. Personally, I think the "promoting cracking" theory is a bit outdated now with most reputable manufacturers casting the discs with the holes in them rather than "drilling" them through a solid disc. I would have thought that also improved structural integrity but don't know tbh.

FWIW I've never had a drilled disc go on me in some 10 years of use on road and track. I've had at least 3 solid discs go in the same time.

I've not looked into it for a very long time so things might have changed, i'm not sure what difference cast or drilled holes will make, the cause of the cracking is the difference in temperatures and metal expansion.

G J · 27 Mar 2012 at 15:39

Check the other side of the disc pictured, it could be a lot worse.

Dogbreath · 27 Mar 2012 at 17:39

Firestar_3x said:
I've not looked into it for a very long time so things might have changed, i'm not sure what difference cast or drilled holes will make, the cause of the cracking is the difference in temperatures and metal expansion.

The cause of cracking is the stress concentrations caused by the holes. That said even plain discs crack.

Scania · 27 Mar 2012 at 18:32

Firestar_3x said:
Drilled holes in the disc offer performance benefits; this is why the above manufactures decide to use them. However it also reduces the structural integrity and promotes cracking and in some cases causing catastrophic failure of the disc through the drilled sections.

Indeed, which is why I'm yet to see a drilled disc fitted to an HGV.

Scania · 27 Mar 2012 at 18:34

Double post.

Phate · 27 Mar 2012 at 18:35

I had a similar issue recently (albeit mine looked worse than yours) and it turned out to be a seized caliper for the handbrake.

Enjoy

phil675 · 7 Apr 2012 at 13:43

So, an update. I finally got round to having a look at this. I took the brake pads out, cleaned the disc, pads and caliper with brake and clutch cleaner, put it all back together and the grinding noise when moving and braking has stopped, braking is generally smoother than before. Woohoo

Philz0r · 7 Apr 2012 at 15:46

What about grooved disc's? I heard they chew through pads? Is this true?

Clarkey · 7 Apr 2012 at 19:25

Don't know about that but they don't improve the braking and they do make a horrendous din when you are braking.

Princey · 7 Apr 2012 at 19:58

Clarkey said:
Don't know about that but they don't improve the braking and they do make a horrendous din when you are braking.

Mine don't? :confused:

Firestar_3x · 7 Apr 2012 at 20:00

Princey said:
Mine don't?

Mine used to make a faint turbine woosh type noise, hardly a din imho.

Lopéz · 7 Apr 2012 at 20:04

My grooved discs make a sort of thrumming noise when I do a seriously big stop, otherwise I don't notice them.

Clarkey · 7 Apr 2012 at 20:07

Well, mine were certainly pretty darn noisy, loud enough that passengers would always comment on it. Did my head in tbh, total silence on plains now, bliss.

nicRob · 7 Apr 2012 at 20:53

I find my grooved disks annoying too, changing to plain soon.

Gaijin · 7 Apr 2012 at 21:41

My old grooved discs made a fan-like whooshing sound but it wasn't that noticeable. But then again I don't really find brake squeal that irritating either. Some people act like it's the end of the world.

danza · 8 Apr 2012 at 00:03

Gayjin said:
My old grooved discs made a fan-like whooshing sound but it wasn't that noticeable. But then again I don't really find brake squeal that irritating either. Some people act like it's the end of the world.

You should've heard mine in my CTR. It was so loud I was sure pedestrians could hear it. I was embarrased to apply the brakes, even at low speeds. I had enough when they started vibrating the dash, and then went back to plain discs.