Warped brake discs - is it me??!!

Warped brake discs - is it me??!!

Author
Discussion

eltax91

Original Poster:

9,842 posts

205 months

Friday 17th July 2015
quotequote all
Hi guys

I'm starting to feel a little self conscious! I used to have trouble an octavia I had, whereby I'd (myself) fit new discs and pads, and within around 20k miles the discs would warp. This is around 8 months driving for me. I would manage it for another few months and then change them again. Over 4 years ownership I tried and warped 4 different brand of disc, halfords, apec, mintex and even a set of expensive brembo!!

Whenever I asked friend in the trade or forums, they all said 'common fault don't worry'.

Then I swapped to another octavia and the same happened to that one. Ok thinks I, common fault. Same story on my wife's A3 only she was making them last longer on average.

The I stopped with the vag cars and I have an e61 5 series. Sure enough, after 6 months I started to get the tell tale signs of warped discs. I changed them and before I sold it 6 months later the slow pulsing through the peddle was there again on light braking.

Now I've been in an accord tourer for around 2 years and I've seen off the set of discs and pass that came with the (second hand) car and around 12 months since I changed them, this new set are at it again!

So, what's it with my driving style that does this? I'm getting rather paranoid that cars hate me. hehe

Or is it something I'm doing when I fit them??!! That's the other possibility I suppose.

Yours, dazed and confused of Leicester. smile

kambites

67,461 posts

220 months

Friday 17th July 2015
quotequote all
I don't know what causes it but our Octavia is still on its original brake discs after nine years and 90,000 miles as is the Elise after eleven years and 50k.

Edited by kambites on Friday 17th July 08:01

bobtail4x4

3,701 posts

108 months

Friday 17th July 2015
quotequote all
after heavy braking do you sit with your foot on the brake?

that causes warping.

chrisga

2,087 posts

186 months

Friday 17th July 2015
quotequote all
No expert but do you always sit with your foot on the footbrake after either long or hard braking? Could it be that the discs heat up and cool differently where the pads are touching? Once the discs start to warp the wheel might always stop in the same place exacerbating the problem.

kambites

67,461 posts

220 months

Friday 17th July 2015
quotequote all
bobtail4x4 said:
after heavy braking do you sit with your foot on the brake?

that causes warping.
Ah that would make sense I suppose - if you sit stationary with your foot on the brake, the discs will cool down unevenly which might cause them to warp.

mini me

1,435 posts

192 months

Friday 17th July 2015
quotequote all
When you fit them do you clean up the hubs or are you just removing old and slotting on the new?

Dodsy

7,172 posts

226 months

Friday 17th July 2015
quotequote all
disks dont warp. What happens is you get pad material transferred unevenly leaving a high spot on the disk. So as you brake every time that spot passes under the pad you get more grab.

Its caused by sitting with your foot on the brake pedal with hot pads. Do you come off a motorway, brake reasonably hard to a stop then sit on the brakes ? Or have a spirited drive then end up at some lights sat on the brakes ? Easiest way to avoid - when you come to a stop release the brake and put on the handbrake.

I havent 'warped' my brakes in over 20 years now so this does work

http://www.mossmotors.com/SiteGraphics/Pages/brake...

Pistom

4,916 posts

158 months

Friday 17th July 2015
quotequote all
Nothing has changed in my breaking technique but I find the same. Discs needing to be changed sometimes twice a year.

Must be due to global warming.

kambites

67,461 posts

220 months

Friday 17th July 2015
quotequote all
Dodsy said:
Its caused by sitting with your foot on the brake pedal with hot pads. Do you come off a motorway, brake reasonably hard to a stop then sit on the brakes ? Or have a spirited drive then end up at some lights sat on the brakes ? Easiest way to avoid - when you come to a stop release the brake and put on the handbrake.
Why doesn't the hand brake cause the same problem?

Studio117

4,250 posts

190 months

Friday 17th July 2015
quotequote all
kambites said:
Why doesn't the hand brake cause the same problem?


Handbrake doesn't use the pads..

  • not in all cases** though

cheesesliceking

1,571 posts

239 months

Friday 17th July 2015
quotequote all
kambites said:
Why doesn't the hand brake cause the same problem?
maybe because it doesnt work the same way the caliper does.

eltax91

Original Poster:

9,842 posts

205 months

Friday 17th July 2015
quotequote all
Hi guys. Thanks for the speedy replies!

The 5 series and the accord are box slush 'boxes, so yeh, after any heavy braking if I'm stopped for a short period of time I'll hold it on the foot brake.

The octavia were both manual though. Although all my driving in these cars is pure motorway, I live 2 miles from the m1 and it feels like I spend my life on M roads. biggrin

I guess at all points though I'm braking down a slip road and sitting at lights often. Although I wouldn't say I braked very early on slips, I'm not last of the late brakers either.

eltax91

Original Poster:

9,842 posts

205 months

Friday 17th July 2015
quotequote all
In answer to the question about cleaning the hub. Always, every time. Brake cleaner on the mating surface, wire brush off deposits and a dab of copper grease.

northwest monkey

6,370 posts

188 months

Friday 17th July 2015
quotequote all
Studio117 said:
kambites said:
Why doesn't the hand brake cause the same problem?


Handbrake doesn't use the pads..

  • not in all cases** though
Well, everyday's a school day!

I just assumed when you pulled the handbrake it just used the rear pads / calipers.

How does it work?

Studio117

4,250 posts

190 months

Friday 17th July 2015
quotequote all
northwest monkey said:
Studio117 said:
kambites said:
Why doesn't the hand brake cause the same problem?


Handbrake doesn't use the pads..

  • not in all cases** though
Well, everyday's a school day!

I just assumed when you pulled the handbrake it just used the rear pads / calipers.

How does it work?
The shoe expands onto the inside of the bell(of the disc) when the cable is pulled.


kambites

67,461 posts

220 months

Friday 17th July 2015
quotequote all
Studio117 said:


Handbrake doesn't use the pads..

  • not in all cases** though
Ah. It does on my car. smile

I suppose the rears are less likely the suffer anyway since they generally run less hot.

TA14

12,722 posts

257 months

Friday 17th July 2015
quotequote all
I doubt that they are warped discs: http://www.stoptech.com/technical-support/technica...

Accelebrate

5,244 posts

214 months

Friday 17th July 2015
quotequote all
At least one of my cars uses the pads for the handbrake, however I would imagine the rear discs never get as hot as the front discs.

mini me

1,435 posts

192 months

Friday 17th July 2015
quotequote all
Next time it does it, or if it is doing it now. Go for a drive and when you find yourself able to WRT safety/ people around/ behind etc give it some uber hard braking a couple of times. Don't actually stop though just very hard on the pedal down from a good speed and then carry on trundling along so the discs cool again. This will often clear any deposits on the disc. Works well on track where this is a common issue with road cars. Don't do it too much though just a couple of good stamps on the brakes should clear it up if its not too bad.

Dodsy

7,172 posts

226 months

Friday 17th July 2015
quotequote all
Handbrake varies by car - Some cars the handbrake acts on the rear brakes pulling them on, others have a separate brake just for the handbrake.

If doesnt case a problem at the rear as most of the braking force comes from the front, so the rear brakes dont get as hot. This is why you see cheaper cars with rear drum brakes and front disks. As most braking force is at the front rear drums are fine for smaller cars and are cheaper.

Rear brakes do still get hot but not hot enough to cause pad transfer. But it can cause handbrake issues. My TVR after a run is parked up with the handbrake full on and it holds the car. Give it half an hour for the rear disk to cool down and it contracts slightly which slackens of the handbrake and car will slowly creep down my sloping drive until it hits the house. I was always told to leave a parked car in gear and still do it today.