grinding lipped brake discs

john east

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Nov 9, 2011, 3:13:25 AM11/9/11

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Nine year old Corolla has just had the brake pads replaced and because they
were squealing the garage sanded down the brake pads, but they are still
noisy. The discs are 'lipped' (Car has done 75K miles) and we are told that
must be the reason for the continuing noise.

Looking on the internet, I see people have said take a file to the lip or
put a grinding wheel in an electric drill and grind away the lip. Could I
reasonably ask a mechanic to do the job like that or would it be cheaper to
buy new (or secondhand discs) from somewhere? Grateful for some basic
advice on what best to do and with keeping the cost down. Thanks.

Mrcheerful

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Nov 9, 2011, 3:22:32 AM11/9/11

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new discs are very cheap and should have been fitted at the time that the
new pads were. Buy a matched disc and pad kit and fit the whole lot
together.

john east

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Nov 9, 2011, 5:00:47 AM11/9/11

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"Mrcheerful" <nbk...@hotmail.co.uk> wrote in message
news:fLquq.17023$604....@newsfe05.ams2...

------------------------------------------------------------------------------

Thanks but the pads have already been fitted. Went to the online 'express
car parts' and total cost of four discs comes to £150 or so. Surely someone
grinding off the discs has to be a more cost effective option please?

Mrcheerful

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Nov 9, 2011, 5:19:17 AM11/9/11

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if the disc is lipped enough to cause a problem then it needs to be
replaced. It will not be cost effective to have your discs reground (which
they could be if they are still thick enough, have you checked?) and the
results are unlikely to be as good as a new set, brakes are an essential
part of a car and scrimping on them is very unwise.

Cecil

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Nov 9, 2011, 5:30:16 AM11/9/11

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The lip has nothing to do with a squeal. Try copper grease

Chris Whelan

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Nov 9, 2011, 6:33:59 AM11/9/11

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On Wed, 09 Nov 2011 10:00:47 +0000, john east wrote:

[...]

> Thanks but the pads have already been fitted. Went to the online
> 'express car parts' and total cost of four discs comes to £150 or so.
> Surely someone grinding off the discs has to be a more cost effective
> option please?

It's more likely that only the front discs are making the noise. You
should be able to find a pair locally for around 50UKP.

Hopefully the discs are not so worn as to be dangerous. If you really
can't afford to spend out on safety-related items for your car, the best
bet would be to put up with the noise; brake squeal in itself is not
always an indication of a fault.

Chris

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Harry Bloomfield

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Nov 9, 2011, 7:45:01 AM11/9/11

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john east laid this down on his screen :

> Nine year old Corolla has just had the brake pads replaced and because they
> were squealing the garage sanded down the brake pads, but they are still
> noisy. The discs are 'lipped' (Car has done 75K miles) and we are told that
> must be the reason for the continuing noise.

I don't think the lip or lack of would make any difference to the
squeal. Usually the lip can simply be chipped away gently with a small
hammer, but I doubt it is causing any issues.

--
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Dave Plowman (News)

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Nov 9, 2011, 8:12:13 AM11/9/11

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In article <mn.4afd7dbb6c...@NOSPAM.tiscali.co.uk>,

Harry Bloomfield <harry...@NOSPAM.tiscali.co.uk> wrote:
> I don't think the lip or lack of would make any difference to the
> squeal.

Don't think so either. Otherwise every new set of pads on old discs would
squeal. Assuming any anti-squeal shims or springs are in place and good,
I'd try a smear of copper grease on the pad backing.

> Usually the lip can simply be chipped away gently with a small
> hammer, but I doubt it is causing any issues.

If it is simply rust if might be - but I'd try doing this to steel.

--
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Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

Dave Baker

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Nov 9, 2011, 12:29:14 PM11/9/11

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"john east" <plan...@mail.invalid> wrote in message
news:j9dcn7$rcb$1...@dont-email.me...

By definition the pads don't touch the lip, or at least new ones will only
just brush it because it's the pads that formed the lip in the first place.
It'll all bed in soon anyway but at 75k it must be well overdue for new
disks if those are original ones. The wear limit is usually about 2mm off
the thickness so if the lip is 1mm on each side they're finished. New pads
on worn disks are not a sensible idea because disks don't wear evenly so the
new pads won't contact them properly and the cost of skimming or a mechanics
time will far outweigh the cost of new disks.

If a disk is worn enough to need skimming it's worn enough to need replacing
basically. Having said that if you have your own lathe like me and your
time's your own then I always lightly skim a part worn disk when I change
pads just to get a perfect contact surface. It wouldn't be cost effective to
do it for anyone else though.
--
Dave Baker

GB

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Nov 10, 2011, 7:27:46 AM11/10/11

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Dave Baker wrote:
>Having said that if you have your own lathe like
> me and your time's your own then I always lightly skim a part worn
> disk when I change pads just to get a perfect contact surface. It
> wouldn't be cost effective to do it for anyone else though.

You have your own workshop and build engines IIRC? I don't think that many
of us are in the same league.

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