Brake Disc

[asm51]

I've just noticed the front offside brake disc on my car is badly scored. There are about a dozen concentric rings of which three are quite deep. All the other discs are fine and I've not had any warning lights show. Although the car is now four years old it only has 10800 miles on the clock. I do a lot of short journeys but I am certainly not heavy on the brakes as such. I'm assuming the pad has worn out, although the bit I can see looks OK. Isn't this a very low mileage for the pads to wear out? Golf GT TSI 160 August 09

[Divhope1]

Could maybe be some part of the bad has slightly chipped and has been sitting between pad and disk do u hear any noises when breaking gently ?

[asm51]

From new I have occasionally heard a rubbing noise from the discs but not often and not severe. The scorings are also distributed across the disc. I would have expected this would not be the case if a bit of pad or other foreign object caused the damage.

[Divhope1]

I have a mk5 gti n my pad had a very tiny bit between the disk and pad and when i gently pressed the break it would squeek and that scored my disk ?
Only thing i can think of mate

[vwcabriolet1971]

Most "disc grooves" are caused by road stone chips ( granite chips are a lot harder than cast iron !). I've had a few over the years but all have been accompanied by fairly loud brake grating noises. I'm not sure that disc grooves would be an MOT problem as long as the braking performance/balance is O.K. but it might be wise to replace the scored disc and pads (both sides). You may get away with replacing just the scored disc if the others show minimal wear and are free from "grooves".Pads shouldn't be worn out after 11K miles with normal use & disc wear should be quite low. It certainly doesn't pay to drive at normal speeds over freshly laid road chippings.

[asm51]

I doubt the disc grooves have been caused by stone chips, there being some 20 grooves, a few deeper than others, spread across the disc, on only one wheel. I can't imagine one wheel picking up 20 odd bits of grit and the other three wheels nothing. I suspect a fault in the pad or calliper or even the system that occasionally applies a little braking pressure to dry the discs in wet weather having gone crazy on that wheel.

[vwcabriolet1971]

Without seeing the grooves it's difficult to guess what caused them . A small number of stone chips or rust chips may have broken up and embedded themselves into the brake pad and spread grooves across the disc . Normal braking action or even faulty calipers do not cause grooves. Grooves are caused by foreign objects between the disc and pad. Due to the very low milage over 4 years the disc may have become quite rusty with rust particles becoming embedded in the pad.

[zollaf]

i would just fit new discs and pads to both sides and forget about it. its possibly down to rust and being too gentle on the brakes, so a good hard emergency stop every now and again to keep them fresh.

[discobarry]

Yeah just replace them and stop thinking about it so much, they will of probably gone like that over time with the little mileage you have done and sitting inbetween use rusting slightly when the air is moist.

[slowhand]

Not much help now but at that low mileage I am guessing that rust might be the cause, do you keep the car outside? do you leave the discs wet after washing or drive to dry them off.
It is possible that the pad got some rust bits on it which scored the disc.
Though I did have one of mine replaced after about 6 months due to scoring, I have no idea what caused it.