Brake disc warranty

takman

Joe_Horner wrote: »

That's true only with the provisos in the bit I quoted pabove. Poorly fitted disks can and do warp because of uneven stresses
in the metal.

Part of my job involves bending steel parts at blue temper without breaking them. You work the two sides unevenly and the surface stresses created cause the metal to curl to one side. It doesn't take much force (or you'll break it - blue steel isn't very good at bending) just a lot of repetitive burnishing or light hammering.

That's exactly what happens with a disk that's mounted with too much runout - the pads alternately work one side then the other on every revolution of the wheel and, over enough repetitions (typically around 10 per second @ 60mph), the metal bends even under relatively light force.

Yes i wasn't considering poorly fitted discs when i made that comment.

forgotmyname wrote: »

So because they say they have not experienced a warped disc and created a page with various myths that i have never heard of they are right and i am wrong when i HAVE experienced a warped disc?

MYTH 2, Racing discs are steel? Never heard anyone say that.
MYTH 3, A soft pedal is brake fade. Not heard that either.
MYTH 4, never heard anyone say that. You would need someone that
knows nothing about cars.

What was the cause of the warped disc and what checks were made to show that it was warped?. Although Joe has said how it can happen most mechanics just say a disc is warped even without basic checks.

Tarambor wrote: »

Or you could have a seized caliper piston or sliders. If you heat the hell out of one side of a vented disc and not the other due to a piston being seized then you can warp a disc.

I went down a 1 in 6 hill a few weeks ago and had to brake hard at the bottom. A few miles later I stopped at some roadworks and there was smoke coming up from the nearside front due to the caliper seizing through lack of use over winter. Cue new pads, disc (because it was warped) and caliper.

I've had warped discs several times over the three decades I've been driving. I've also experienced warped drums on the trucks I've driven too.

Were proper checks carried out to check they were warped or were you just told this by a mechanic. When you caliper seized that could definitely warp your disc but what caused the other ones?.

Like above i think warped discs is a term that is thrown around far to much.

forgotmyname

Cause of my warped discs a Rover SD1 V8 with non vented brake discs and some heavy track use.
Later cars had vented discs but mine had solid. Swapped to vented afterwards. Checked on a large lathe and the discs were 100% warped not a build of of brake pad material etc.

This was back in the day when they were getting silly power figures from Sierra Cosworths which could actually set fire to their brakes if they didnt explode first.

Also known people to have pads fall out.

Consider the fact that you can bend thick metal just by applying heat to one spot.