Front Brake Discs Badly Scored? Wheel Bearings gone?

[seatcupra]

I just changed my brake discs/pads today as my old ones were badly scored only on the rear of the disc. Now looking at where the score was on the discs it looks like it has been the carrier thats been rubbing the disc. Any ideas to why this would be happening?

Before bolting it back on I gave it a light file to remove some crap/corrosion but once the carrier was bolted back on it's literally sitting 2mm from my new disc at the rear. Does this sound too close for comfort? I don't want to wreck my new discs so thought I'd check if anyone has had same problem?

Cheers
Scott

 

[Slimy]

2 mil is plenty, the disc should not move at all. Even a fraction of an inch play in the disc will make the whole car shake, if the disc moves 2mm I'd be expecting your whole wheel to very shortly overtake you as it comes off!!!

Putting the carrier back round a brand new disc can be a bit concerning, until you realise what sort of tolerances the system is built around. You'll be fine. What I've had to do with other cars is give the carrier a scrub with a wire brush to get rid of corrosion, it sounds like you've already done that which is good.

 

[Seatmann]

Check for play in the rear bearings too because that can allow the hub and disc to move but the carrier wouldn't and the two could make contact.

 

[seatcupra]

2 mil is plenty, the disc should not move at all. Even a fraction of an inch play in the disc will make the whole car shake, if the disc moves 2mm I'd be expecting your whole wheel to very shortly overtake you as it comes off!!!

Putting the carrier back round a brand new disc can be a bit concerning, until you realise what sort of tolerances the system is built around. You'll be fine. What I've had to do with other cars is give the carrier a scrub with a wire brush to get rid of corrosion, it sounds like you've already done that which is good.

Thanks for the reply!

Do you think maybe the carrier wasn't cleaned the last time the discs were done, hence the scoring on the old discs which was bang on in line with the carrier?

Check for play in the rear bearings too because that can allow the hub and disc to move but the carrier wouldn't and the two could make contact.

What's the best way to check this?

 

[Slimy]

Corrosion on the carrier wouldn't cause damage to the discs, although there might be some odd squeaking noises. There may have been something a bit more substantial jammed in there though.

Best way to check play is to put the wheel back on, leave the car in the air and try and move the wheel. Top and bottom movement is bad.

 

[seatcupra]

Cheers, Ive got a horrible feeling I'll be needing two front bearings. As it's definitely been the carriers thats have been rubbing the disc so what seatmann has said seems to add up.

Will take a look in the morning for any wheel movement.

 

[Seatmann]

Lol I just realised you were on about the front discs. I read your post wrong but same thing really except check the front. In the meantime I'll go get more sleep.

 

[Slimy]

Lol I just realised you were on about the front discs. I read your post wrong but same thing really except check the front. In the meantime I'll go get more sleep.

Yeah, that's how I saw it too, I had to go back and edit my first post to make sense!

 

[seatcupra]

Sorry if I didn't make myself clear on the first post. It was clear to me

Jacked the front end up again today, checked for top to bottom movement and both wheels seem fine. Also spun the wheels round and couldn't hear anything untowards just a light rubbing noise with I think was the new brake discs/pads tbh. So pretty sure bearings are fine.

Drove 10 miles or so and checked the new discs and they were fine, so I'll just keep an eye on it for a while, anymore scoring on the same spot as before and I'll put it in to a garage.

 

[Slimy]

For a disc to move 2mm, the top of the wheel would move twice that, and you'd notice. So I think your bearings are fine.

 

[seatcupra]

Yeah so leaves me a bit puzzled to how both front discs were rubbing the carriers?

They were for an Audi S3/TT and from ECP so should have been spot on fitment wise. And if they were rubbing from day one I'm sure I would have heard it?! Been on the car almost 2 years.

New ones are EBC from CRN (grooved) with red stuff pads and feel pretty good considering they aint bedded in yet

 

[Slimy]

If they were rubbing from day one you'd have noticed them fitting badly. I can only think that it was some foreign object embedded in the carrier, that dropped out when you dismantled everything.

I have EBC on mine, but I go for greenstuff pads as I don't drive that enthusiastically. Well, most of the time...