Warped front discs

[FlashBastd]

MY car has warped some genuine discs, with genuine pads, in the space of around 10k of normal driving. Neither my wife or I are especially hard on the brakes, but we still seem to have warped them - perhaps as a consequence of it being an auto, and being sat at lights, etc. with hot discs.

Is this common? Any recommendations on how to avoid it happening again, parts recommendations, etc?

Thanks!

[Davenotouring]

Sitting at lights with the brakes on after some braking and hence the brakes being hot can warp the discs.

Use Park rather than the brakes.

[FlashBastd]

Is it common then?

What about those peeps who really do drive their auto E30s hard, surely they must get through discs like nobodies business!

[Widge]

It's all to do with getting them warm then sitting with the brakes still on and clamping one part of the disc so they cool unevenly. Braking hard won't warp the discs, as long as you don't sit at junctions with the brakes on. Mine were warped, but they had been on the car for 5 years, only doing 14,000 miles in that time and looked nearly brand new.

[FlashBastd]

Well our 10k took two years! Our discs don't look bad, the vibration through the wheel is annoying though.

[Davenotouring]

I think driving hard can warp discs...

I put new discs on my civic a while ago, I don't sit on the brakes at junctions and stuff, and they are warped to fu** now.

The whole car shakes upon braking at 80mph

[Widge]

Hmmmm it's interesting this, cos when you look at the vented frons on an E30 it amazes me how they can warp they're so Fing thick! Maybe if you really cook them it would do it. It's not like you take any prisoners with the civic

[FlashBastd]

Well they will have come from EuroCarParts, so maybe they were patterns and not genuine. We will see how the next set fair.

[Widge]

Alot of the time the EPC stuff falls off the same production line as the BM stuff, but only after the BMW roundell has been removed from the machine

[FlashBastd]

but they do varying grades of quality though, right?

[Dan318-is]

i would say brakign at junctions would do it, happened to my dads TVR

use the parking break when possible i owuld recommend

[Jackle]

I had a warped disc on the front of my old car, turned out to be a sticking brake caliper. I could feel the resistance when driving, and when I stopped the wheel was hot to the touch. Changing the caliper and discs sorted it.

[E30Adam]

There's actually no such thing as warped discs, have a look at this site and all will be explained

http://www.stoptech.com/whitepapers/war ... s_myth.htm

[Widge]

Ah adam the font of all knowledge................

[johnono]

ok then ill be looking at the set up then

[Emotechnik]

There's actually no such thing as warped discs, have a look at this site and all will be explained

http://www.stoptech.com/whitepapers/war ... s_myth.htm

Of course a disc can warp, however it should be correctly termed as disc 'run-out' (out of true) and a qualified mechanic can check the 'run-out' with a commercially available DTI.

BMW even publish max figures for run-out and accept this under warranty if their product fails to meet standard.

That article you link to is about pad pick-up on the disc surface which then causes an irregular surface and hence vibration, vibration can also be caused by rust forming only where a ferrous content pad has been in contact with an iron disc in wet weather.

[Emotechnik]

Ah adam the font of all knowledge................

BMW Website (font) about Checking brakes for "run-out", warping

http://www.autohausaz.com/bmw-auto-part ... rakes.html

[Martinaston]

If it's taken two years for the vibration to show i suspect it may be due to rust expansion between the hub surface and the disc that has pushed the disk out of true.
Take the disc's off and attack the mating surfaces with a wire brush before you fork out for a new set and see if it improves things.

[Emotechnik]

If it's taken two years for the vibration to show i suspect it may be due to rust expansion between the hub surface and the disc that has pushed the disk out of true.
Take the disc's off and attack the mating surfaces with a wire brush before you fork out for a new set and see if it improves things.

The disk is 'clamped' between the hub and the wheel, and this as we all know is with 4 big bolts at circa 80 lb/ft torque, if the rust was pushing the disk out of true then the wheel would also be out of true, and he's not complained of any wheel vibration without braking.

If rust could push a disk/wheel away from the hub (when torqued up correctly) then I'm worried

My guess is through lack of use their will be a rusty pad imprint on the disk surface, this high friction area gainst the rest of the disk will cause brake force fluctuations (vibration) under braking.

Take the disc's off and attack the mating surfaces with a wire brush before you fork out for a new set and see if it improves things.

Excellent idea when replacing discs.

Let's see some pic's of the disks.

[Martinaston]

It was only a suggestion, he may have had a puncture recently and moved the disk while changing the wheel.

The guy said he doesn't exactly race the thing so if he's got soft tyres he may not have noticed the wheel wobble.

[Martinaston]

Emotechnik
Have you ever heard of breaking rocks with water?

[Emotechnik]

Back atcha

[Widge]

Chill Winstons!

[johnono]

Chill Winstons!

[Widge]

Well they were gettin right bitchy (well not really I'm bored)
I could see one of these coming on ...

[Emotechnik]

Well they were gettin right bitchy (well not really I'm bored)
I could see one of these coming on ...

Yes I agree, lots of boring threads on the zone this weekend

[Widge]

I meant a bitch fight not boredom induced lesbianism

[Martinaston]

Well the last time me and a friend tried to liven the place up people started to winge and nearly got me banned so bollocks to it, i'll leave it to you lot from now on

[johnono]

I meant a bitch fight not boredom induced lesbianism

i dont mind a bit of boredom induced lesbianism

[Emotechnik]

I could see one of these coming on ...

Remind me again, which one of these is you?



Good luck with the 2.7 crank this time

[Emotechnik]

I could see one of these coming on ...

Remind me again, which one of these is you?



Good luck with the 2.7 crank this time

[Martinaston]

johnono
If your a bird, Your one hairy bird

[johnono]

i didnt mean takin part.... just takin it in

[Martinaston]

Well if i was forced to watch that kind of filth i would have to do so grudgingly

[Widge]

Johnno, I knew you would like it

None of them are me, its a random web pic

Just brightening up everyone's night!

I hope the crank works out too.