New Disc Coating Issue

[Wayne.R]

Afternoon all.

Quick question/query regarding new discs and pads.
2 days ago I fitted new discs and pads to the car. Pads were nearly down to metal, and discs were lipped badly.

This was a selling point, when I purchased the car.
So not a surprise.

Yesterday was the first drive of the car, aside from some, too'ing and fro'ing to ensure correct fitment.

Now, the offside is squeeling loudly at slow speeds, and when looking over the brakes, I can see that some of the disc coating is still present, whereas the nearside, is completely fine and no noise.

The car isn't pulling and drives nicely. Brakes have a proper bite again.

I'm racking my brain to understand why this coating wound remain, and not burn off from brake applications.

Any ideas?

I didn't grease the slide pins, and they were moving nicely, though I don't think this would be a cause either.
Discs are AE Motorsport supplied and Pads are Brembos, supplied by AE Motorsport (UK)

Images supplied for viewing.

Cheers

W.

[madstaff]

Give it a while and it'll wear off when the pads have bedded in.

Probably the pads aren't properly true and flat.

My other half's A1 did exactly the same after I recently replaced the rear disc pads.

[Redreels]

I would suggest applying some copper grease to the back of the pads to stop the squeal.

[Adam T7]

Give it a while and it'll wear off when the pads have bedded in.

Probably the pads aren't properly true and flat.

My other half's A1 did exactly the same after I recently replaced the rear disc pads.

As did my 7.5 a few months ago when I got fresh pads fitted on the front. Took about 500 miles to disappear.

[Wayne.R]

Cheers all. It's gradually wearing off, though taking it's time. Squeeling is loads less too. Need some fairly decent brake applications, to get it gone I've noticed. Regular braking isn't doing much.

I may whip the pads out and apply a little bit of copper in the pad carrier channels and back of the pad for good measure.

[EB2019]

I wouldn't bother taking them back out, they will wear flat, but currently one of the surfaces isn't flat (pad or disc).  But I don't know the quality of the discs, does it say pagid on the 3rd image near the wheel?
If they are pagid/brembo its possible ECP supplied, and we have had a lot of customers notice squeal with them.

if you look at the back of the pad you can see the thin fabric pad on the back of the metal backing plate.  This is all you need on the back of the pad, to prevent squeal, if you have squeal putting, copper grease on the back plate won't really help.  It could just be that you need a few hundred miles.

Assembly lines are fitting brakes dry so you shouldn't need much of anything, but a little ceramic grease is ok on the pad 'ears'.

Give it a few hundred miles and if it doesn't improve send them back.

[MervJnr]

I wouldn't bother taking them back out, they will wear flat, but currently one of the surfaces isn't flat (pad or disc).  But I don't know the quality of the discs, does it say pagid on the 3rd image near the wheel?
If they are pagid/brembo its possible ECP supplied, and we have had a lot of customers notice squeal with them....

I've done this. Replaced discs and pads all round with Brembo parts, supplied from GSF. Bought them myself and a garage fitted them for me as they were quoting way more for the parts.

Done many miles on them now and they still squeak. A spell of hard-ish braking and the squeal stops but I get judder / uneven braking. Guessing this is a warped disc...

[clubsport]

Response to MervJnr,

Very often, but obviously not always, the symptom you describe can be down to an uneven accumulation of pad dust on the disc.

The best way to resolve this, is to remove the pads and rub them across a flat sheet of emery paper to flatten the surface, the pads should dull any glaze on them. Next to rub the surface of the disc with fine emery paper to remove any accumulation of dust/pad.

I have had this quite a few times after track days, where the brakes have been used hard (not in the Golf!). In your case maybe the pads were not bedded in as required?

[MervJnr]

Response to MervJnr,

Very often, but obviously not always, the symptom you describe can be down to an uneven accumulation of pad dust on the disc.

The best way to resolve this, is to remove the pads and rub them across a flat sheet of emery paper to flatten the surface, the pads should dull any glaze on them. Next to rub the surface of the disc with fine emery paper to remove any accumulation of dust/pad.

I have had this quite a few times after track days, where the brakes have been used hard (not in the Golf!). In your case maybe the pads were not bedded in as required?

Thanks for the advice, I'll give this a try.