Advice needed - brake discs

[JoolzB]

I'm just after a bit of advice, my sisters car had its brake discs replaced 29th November, it's a 52 Diesel Leon. The brakes have warped after 8k miles and Seat are blaming the cause on heavy braking, the discs were warranteed for 6k miles. Are they being unreasonable?

mods. will this be better in GG?

>> Edited by JoolzB on Tuesday 28th February 10:21

[zippee]

Could well be a combination of cr4p discs and heavy braking. I had a 4th gen Honda Prelude and had new discs put on, after only a couple of thousand they'd warped again. The garage that did the work resused to do anything so I had to upgrade to a performance disc which solved the problem.

[Trooper2]

Rotors warped due to heat would I think have 2 tell-tale signs 1) heat checking- fine cracks in the braking surface and 2) a blue tint due to the heat.

Rotors can be warped easily by many things to include over torquing or not torquing in a proper pattern.

[Parrot of Doom]

Tell the dealer thanks very much for their time, and that you'll never ever buy anything from them ever again.

[Mr Whippy]

Heavy braking?

Surely the brakes should be able to cope with heavy braking with even the OEM pads.

The only time OEM's should warp is if the pads are uprated and cook the discs!?

Again, what good is a warranty if they just blame the problems on you?

Dave

[JoolzB]

I wouldn't say the car has been caned, it's been used on a daily basis on longish journeys.

[Egbert Nobacon]

Often warped discs can be caused by people leaving the brakes applied, whilst stationary, after braking from speed, say at the end of a slip road off a motorway - the heat from the pads applied to one part of a disc for say 20 secs can lead to a distortion.

I had a VW Golf fleet car with a similar issue - 3 sets of discs replaced, all warped - caused by a combination of the above and pattern discs being used for cost saving reasons.

[pistol pete]

Brake discs don't (usually) warp.

The judder -I assume thats the problem -is usually caused by a build up of pad material in one place on the disc. This is caused (usually when the brakes are not bedded in properly) by holding the brakes on when the car is stationary and the pads/discs are hot and the pad material bonds to the disc. At least if you use the hand brake, then the rear brakes -which are usually not as hot suffer the (lesser) problem.

This is also why you should not hold the car by it's brakes when you come off a track, as they have not had time to cool down.

If you take the car for a hard run and try to get some heat into the new brakes, then they should still bed in properly (an even layer of pad material all round the disc). Some manufacturers used to always recommend 10 progressively harder stopped from 60mph to gradually build up heat in the brakes. During this, you must not actually come to rest as obviously this would make the pad material grab the disc in one place. then drive gentally for a while to allow the brakes to cool down before they touch a stationary disc. I assume this advice hasn't changed.


Not that any of this is usually needed for a modern road car, and may well be because the dealer used cheap parts!

Pete

[Mr Whippy]

My latest OEM's, 3 people in car, 60-10 ten times at ~ 75% braking force upto ABS/lockup level, then cool right down for a few mins at moderate speed, then repeat.

Thats them bedded in!

Sooooo sooooo good too. After the first set they started to smoke alot, but the second set of stops were just silly performance wise. I didn't know brakes could be so good once warm...

Good bedding in, and not sitting after a long braking session (motorway/slip-road speeds > 0mph) with the foot on the brakes. Slow to an almost stop about 2 car lengths early then just edge forwards slowly so the brakes are not on for long with the car stopped.

As long as you are not tracking the car, I don't see how you could warp decent OEM spec brakes on the road without knowingly overheating the brakes then leaving the pedal pressed at a standstill all day!

Dave

[twelve_75]

Surely you'd smell them first?

[jap-car]

Hoe do you know the discs have warped? Have you removed the wheel and rotated the disc against a fixed point? A judder is often down to a sticking caliper.

[JoolzB]

jap-car said:

Hoe do you know the discs have warped? Have you removed the wheel and rotated the disc against a fixed point? A judder is often down to a sticking caliper.

I don't and the dealership don't know either as they've not seen them, the car judders apparently. I've now spoken to the dealership who are unwilling to change them for nowt (if they are warped) but Seat Customer Service seem a bit more reasonable but I'll wait and see.

[monkeyhanger]

I seem to remember a few cases of Skoda changing Octavia discs under warranty for juddering, with a lot more than 6K on them.

Another little VAG characteristic it seems

[Mr Whippy]

If they won't do them for free, DIY. One of the easiest jobs there is, and the discs won't be silly money if you get OEM but not from the stealer... Maybe £80-100...

Then bed em in and see what happens... could just be a poor OEM disc? What size are they, a bit too small for the cars weight?

Dave

[JoolzB]

Mr Whippy said:

Then bed em in and see what happens... could just be a poor OEM disc? What size are they, a bit too small for the cars weight? Dave

Definitely worth a thought, this dealership certainly won't be getting the work if they do need replacing at cost. I was wondering about the size aswell, it does seem a bit strange that the car will be on it's third set already and it's not that old. I'd've imagined that Seat would have had numerous problems though with them and they haven't mentioned an upgrade.

[JoolzB]

anonymous said:

[redacted]

I'm not from Norfolk.

We took the car in this morning and according to matey the disc hadn't blue'd up so there was no sign of it over heating. I had a look afterwards and it looks like there's a crack in it which wasn't mentioned, he reckoned that it was safe to drive on but I would have thought that juddering due to a cracked disc was pretty bad? Any advice?

[tr7v8]

Could be DTV or disc thickness variation. This is quite common if the discs aren't square
on the hub, they then wear unevenly. Normally caused by muppet mechanics not cleaning the shite off the hub properly.
Oh and on some cars warped discs are very common!

[Mr Whippy]

I've had cracked discs, blued discs and all manner of things that look dodgy, and they never get that bad imho.

My 306 had blue discs for a while before I changed them for all OE kit, and even then they were not that bad, however the pad material had come of the back plate, which WAS pretty bad!

I rekon that when they were done they put on cheap parts. Not sure if they do that, but why would OE stuff fail like that?

I've done 20,000 mile on brand new OE stuff, and hard ish miles too, and they just keep going (XR4x4 and Tdi 405) and had plenty of life left.

Something sounds wrong for them to be failing so easily! Be it crappy parts or faulty brakes!?

Bad batch of discs maybe?

Dave

[JoolzB]

Well we've spoken to Seat and they're gonna replace the discs free of charge, it appears that mateys assumption of "heavy braking" was a bit unfounded.

Anyway, thanks to everyone who posted any advice and info on the matter