Bedding In Pads?

Author
Discussion

MondeoMan1981

Original Poster:

2,441 posts

197 months

Saturday 24th June 2023
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Got new pads fitted nothing special just what the factors supplied the mechanic so generic. Noticed they arent clearing up the disc and a band of oxidisation remains. Old pads were fine no issues at all other than having served their time.

How long to bed in? These have had 150 miles and I've done two runs of specific varying braking events including some harder braking.

Pic for info. Is something scoring the disc in towards the hub?





Grumps.

11,301 posts

50 months

Saturday 24th June 2023
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Does it stop as usual when you brake or do you have to apply a bit more pressure?

MondeoMan1981

Original Poster:

2,441 posts

197 months

Saturday 24th June 2023
quotequote all
Grumps. said:
Does it stop as usual when you brake or do you have to apply a bit more pressure?
I'd say it feels fairly normal. I don't think the pedal is "long" or anything like that. Plenty bite in them, I've done a few 60-20 at the end of slip roads etc.

BertBert

20,283 posts

225 months

Saturday 24th June 2023
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If the pads previously swept a larger area (radius) of disk, then you have the wrong pads in

d_a_n1979

11,446 posts

86 months

Saturday 24th June 2023
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Do some hard but safe braking, 70-40mph a few times to get them hot and then drive normally for 10mins to let them cool down etc...

If the discs haven't cleared by then, then you need better/proper fitting pads!

ninepoint2

3,684 posts

174 months

Saturday 24th June 2023
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BertBert said:
If the pads previously swept a larger area (radius) of disk, then you have the wrong pads in
This ^^^^

finlo

3,903 posts

217 months

Saturday 24th June 2023
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ninepoint2 said:
BertBert said:
If the pads previously swept a larger area (radius) of disk, then you have the wrong pads in
This ^^^^
I think the rusty bit is the edge rather than the face.

J4CKO

44,218 posts

214 months

Saturday 24th June 2023
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Fit them the day before a track day, that beds them in nicely.

Brakes now vibrate like fk in a hard stop but they are very effective.

MondeoMan1981

Original Poster:

2,441 posts

197 months

Saturday 24th June 2023
quotequote all
finlo said:
ninepoint2 said:
BertBert said:
If the pads previously swept a larger area (radius) of disk, then you have the wrong pads in
This ^^^^
I think the rusty bit is the edge rather than the face.
It's the face. Just over 1cm of it.

One side is better than the other but I'm not sure if that's just because one side was more exposed to the elements!

E-bmw

10,952 posts

166 months

Sunday 25th June 2023
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As has been said above, you need to check the pads sweep the full disc surface.

If they do then the likelihood is that there is a more worn down area that is showing as rusty because the pads don't yet touch it.

GreenV8S

30,800 posts

298 months

Sunday 25th June 2023
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I think the problem you've got is that the rust is so coarse that it's chewing the pads up faster than the pads are wearing down the rust. That's probably not going to fix itself. To fix it, you could either replace the discs or get them skimmed.

5s Alive

2,447 posts

48 months

Sunday 25th June 2023
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Agree with GreenV8S that's not going to clear with braking and looks like much older corrosion than acumulated during the last 150 miles.
I've had past success with a flat sanding block on both disc and pads if you're able to remove them yourself.

MondeoMan1981

Original Poster:

2,441 posts

197 months

Sunday 25th June 2023
quotequote all
GreenV8S said:
I think the problem you've got is that the rust is so coarse that it's chewing the pads up faster than the pads are wearing down the rust. That's probably not going to fix itself. To fix it, you could either replace the discs or get them skimmed.
Weird as that disc face was pristine 1 week ago....

E-bmw

10,952 posts

166 months

Monday 26th June 2023
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MondeoMan1981 said:
GreenV8S said:
I think the problem you've got is that the rust is so coarse that it's chewing the pads up faster than the pads are wearing down the rust. That's probably not going to fix itself. To fix it, you could either replace the discs or get them skimmed.
Weird as that disc face was pristine 1 week ago....
Yes, but that was with pads that had worn to the disc surface, which just proves that the disc surface at the edge is lower than the surface that has been cleaned by the swept area of the pads, or that the pads are too small.

steveo3002

10,803 posts

188 months

Monday 26th June 2023
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you can see the inner rust lip is stopping the pad contacting the main part of the disc , ideally you would have knocked that off with a grinder both sides , you will just have to wait until the rust lip cuts a groove into the pad

GreenV8S

30,800 posts

298 months

Monday 26th June 2023
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MondeoMan1981 said:
Weird as that disc face was pristine 1 week ago....
Could be simple bad luck that the pads were able to clear the rust from the inner band slightly quicker than the outer and the rust has got established enough to form an abrasive surface. This is what is chewing the pads up. Anyway, it's there now.

MondeoMan1981

Original Poster:

2,441 posts

197 months

Tuesday 4th July 2023
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Just to close this topic off, discs were on offer so I have replaced them as well. Issue pretty much resolved.

Off to the garage today now to get the air con fixed under warranty.

And then in true PH fashion, probably sell it