Issue with new discs and pads on Seat Mii?

[DaGuv]

Had the wife’s car in for new discs and pads. After doing 20 miles I notice this on both discs. White marks. Is this normal? Thanks

[Bobupndown]

Looks to be the protective coating on the discs wearing off as the pads bed in. Check again after a few more miles. The discs should be uniformly shiny over the full contact area.

[snotrag]

Yep it's the remnants of the paint. The whole disc will have been that colour when installed.

[Haltamer]

Needs more miles - It should be getting there in 100 or so; Manufacturers usually state around a 200 mile bed in period at least.

Out of interest, what's the spec on the car? Those discs look huge for a "shopping car" (Perhaps it's just small wheels throwing me off?)

[Tony1963]

I’d be giving them a few hard tests from 60mph down to 20mph a few times, to get pad material transferred to the discs. All should look ok then. Don’t come to a stop with hot brakes if you can help it!

[AlexRS2782]

Haltamer said:

Needs more miles - It should be getting there in 100 or so; Manufacturers usually state around a 200 mile bed in period at least.

Out of interest, what's the spec on the car? Those discs look huge for a "shopping car" (Perhaps it's just small wheels throwing me off?)

Fairly sure they're the factory / option 14" rims on the Mii, so just the angle of the pic making the caliper / disc setup look bigger.

[steveo3002]

yep nothing to worry about , thats just showing why brakes need bedding in , the whole pad isnt making contact yet due to it needing a bit of wear

will go away with normal use or a few hard stops wont hurt

[Smint]

steveo3002 said:

yep nothing to worry about , thats just showing why brakes need bedding in , the whole pad isnt making contact yet due to it needing a bit of wear

will go away with normal use or a few hard stops wont hurt

Correct.
Even more revealing would be to apply the same light paint and see the results after fitting new pads to well used discs, the contact versus unswept area could well be the exact opposite of above, with only 20% of so of pad friction material making contact depending how worn the discs are.