Brake Discs

m4cc45 · 21 Sep 2012 at 16:52

Hi,

Really quick question. I had my brake discs and pads replaced in July 2010. Today I had an MOT whereby it failed on the brakes causing excessive juddering.

I am now being told that the garage 'thinks' it is down to warped discs. I don't mind paying for them if this fixes the issue as I wouldn't want to mess around with brakes but having had them, from brand new, just over two years makes me think twice (and the cars been driven around 13,000 miles since then).

I should also point out that when I had them originally replaced the garage put the wrong discs on originally but as they were replaced with the correct ones I'm thinking that it shouldnt be a problem? Or should I be looking into it more?

M.

shoes · 21 Sep 2012 at 16:58

It's entirely possible that the brake discs are warped, yes. How do you drive - would you consider your driving 'spirited'? How many miles have you done in the two years?

Dale V · 21 Sep 2012 at 17:01

Juddering brakes on an MOT test? Usually you have to get upto some decent speed to brake and notice warped discs, something which isnt possible to do on an MOT, im really not sure you'd notice this on an MOT test

Have you noticed it?

m4cc45 · 21 Sep 2012 at 17:02

13,000 miles in two years - drive 'normally' (if there's such a thing) very rarely brake hard unless a car jumps out in front of me, etc.

M.

m4cc45 · 21 Sep 2012 at 17:03

Dale V said:
Juddering brakes on an MOT test? Usually you have to get upto some decent speed to brake and notice warped discs, something which isnt possible to do on an MOT, im really not sure you'd notice this on an MOT test

Have you noticed it?

That's the thing - I haven't really noticed it at all. Been around 60 miles motorway trips a couple of times in the last couple of weeks and it's been fine.

The reason I'm asking is I think it's bull ****.

But then I haven't been doing any hard brakeing.

M.

Dale V · 21 Sep 2012 at 17:04

If you havent noticed it in normal driving, then they havent noticed it on an MOT test, it is bull****.

m4cc45 · 21 Sep 2012 at 17:05

Hmm time to have words!

M.

Zack101 · 21 Sep 2012 at 18:28

Dale V said:
Juddering brakes on an MOT test? Usually you have to get upto some decent speed to brake and notice warped discs, something which isnt possible to do on an MOT, im really not sure you'd notice this on an MOT test

Have you noticed it?

Brake judder would be checked for on the rolling road. You get fluctuating readings when the discs are distorted.

It is also possible they are mistaken, if you are doing say 60 mph and brake gently progressing through to hard braking, do you feel any shuddering either through the steering wheel or the whole car itself?

Conscript · 21 Sep 2012 at 19:01

Aren't warped discs a misnomer?

I thought it was pretty much impossible to attain the sort of temperatures need to warp a cast iron disc on a road car and that was most people describe as warped discs is actually just to an uneven depositing of brake pad material on the disc surface and/or improperly fitted discs or pads.

Dogbreath · 21 Sep 2012 at 19:58

Conscript said:
Aren't warped discs a misnomer?

I thought it was pretty much impossible to attain the sort of temperatures need to warp a cast iron disc on a road car and that was most people describe as warped discs is actually just to an uneven depositing of brake pad material on the disc surface and/or improperly fitted discs or pads.

It is definitely possible to warp a disc on a road car, and a simple check with a Dial test indicator will show if this is the problem or not.

That said, judder is much more likely to be a problem with the surface of the discs (cheap discs can suffer from uneven hardness ), uneven pad material distribution, corrosion on the hub mounting face causing run out, or even a damaged/bent drive flange or CV joint.

m4cc45 · 21 Sep 2012 at 20:15

To quote the MOT:

Nearside Front brake juddering severely
Offside Front brake juddering severely

I do have to complain though as the parts that they sold me when they replaced are different codes to what they've replaced them with so something is wrong somewhere...

Jonny ///M · 22 Sep 2012 at 00:25

I got the same at my MOT despite it being new discs and pads. I didn't feel a judder too and I brake quite hard and from highish speeds a lot.

Is it possible for a sticky caliper to feel like a judder?