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MG MGB Technical - Squealing disc brakes

Does anyone have a good cure for squealing disc brakes?

I changed the callipers several years ago with new ones from the Bhive, everything was fine for a couple of years then they started squealing while slowing. So far I've tried copper grease on the backs and edges of the pads, 3M anti squeal tape on the backs, changed pads for new ones, abraded the pad faces in case they were glazed, ensured the pistons are correctly oriented but I've still got the problem. Each of the above cures it for a while but it comes back. I'm not talking about a small squeak it’s a very loud squeal that doesn't stop until the vehicle comes to a halt.

The brakes work well with a firm peddle and little travel, the bearing feel good, I can’t detect any undue play in any suspension components and the discs look good with no undue wear.

Bob
R.A Davis

You could try chamfering the leading and trailing edges of the pads, also have you got the pistons in the correct position. Hope this helps.

regards John
john wright

John

From memory the pads are already chamfered but I will check and the pistons are definitely correctly oriented.

Thanks

Bob
R.A Davis

What condition are your rotors in? If slightly warped or scored, they can speed up the movement of the pads in the calipers, and wipe off whatever anti-squeal material that you've applied. RAY
rjm RAY

I've had this a couple of times once with a B, I tried many things, as you have, as the noise was very loud and embarrassing, in the end the noise disappeared, I don't know why, perhaps it was the continuing wear on the discs but it may not have been

based on this experience when I had the noise on another vehicle after going through the usual remedies, as the noise wasn't anywhere near as bad as it was on the B, I just let it to go away, and it did

I'm not saying to ignore it but if the brakes are working well otherwise then when you've been through everything you can perhaps just waiting for the noise to go away *might* work
Nigel Atkins

Ray

Visually the discs look in good condition with little scoring other than normal wear lines, I’ll check them for runout.

Nigel

The brakes are working well but ignoring it’s not an option, my navigator AKA SWMBO has been giving me an ear bashing about it.

Bob
R.A Davis

Going back to a Midget, many moons ago, I had the same problem immediately after changing pads to Ferodo. Stopped when i couldn't put up with the racket and put another make on.
Allan Reeling

a bit of copper grease on rear of pad was recommended to me and i have no squeal on my new pads.
G
Graham Moore

I agree with Allan
Your brake pads have probably got too much metal in them
You need more modern pads - designed for road use
willy
William Revit

Like most people I have suffered with brake squeal on my B,I tried all the normal cures, some of which worked for a time, I tried 3 or 4 different makes of pad, some of which were better than others, but in the end I only cured it with fitting some steel anti squeal shims to each piston, after a lot of searching I came across some from a Peugeot expert/806, once I fitted these I have never had a problem with brake squeal, and I have used the car on quite a few trips to the Alps, which involved driving over some of the biggest mountain passes in Europe, A.T

andy tilney

I thought anti-squeal pads/strips were standard fit - I'm pretty sure I tried with and without them, but perhaps a non-standard set might work better

or a thorough check that the ones fitted are still true and not damaged in any way
Nigel Atkins

Nigel if you are talking about stick on pads then we are talking about something completely different, and again these only work for a time, usually until the piston cuts through them, have a look at the picture I sent, A.T
andy tilney

I spoke to my local PSA dealer about a year ago, and the 806 anti-squeal pads are no longer available.

I've been collecting the large lids from honey jars, and when the anti-squeal stick-on pads wear through I'll make my own copies of the 806's.
John Bilham

Bob,

Only had this issue on my B once - all down to the orientation of the piston. I know you would have already done this but just check on the position of the cutout in the piston relative to the caliper.

Cheers,
C Brennan

Hi Andy,
I wasn't thinking of stick-on but the metal shim type thingies
Nigel Atkins

Exactly the same problem here on the V8 when only changing calipers - refitted the nearly-new pads.

It's something I've had for 30 years on multiple cars, but usually light greasing of all the metal-to-metal contact points of pad, caliper and shim has sorted it.

But with new calipers they started squealing shortly after fitting, despite being greased as usual. Regreasing worked for a few days, several times. Since then I've chamfered the edges, replaced the metal anti-squeal shims with self-adhesive, and subsequently used the offcuts of those on the leading and trailing edges, but each attempt only results in a few days quiet. I did buy some CRC disc brake-quiet but haven't used it yet as at the moment it's only intermittent so largely liveable-with. However no matter how far I've been they always squeal really loudly when pulling up outside my house, the neighbours probably think they are like that all the time.

I had a similar bout on the rear of the roadster, again regreasing cured it for just a few days, but in that case simply swapping the shoes between sides (and maintaining the correct orientation ...) seems to have done the trick as they have been quiet for several years now.
Paul Hunt

The cut-out is interesting. The official MGB manual states the cut-out must face the middle, and Midget manual states that the cut-out must face the bottom - yet both calipers are quite similar, just the obvious difference in scale.
Maybe it's a case of horses for courses, or maybe an error in one or the other.
On top of that, the new calipers we have in stock come with the cut-out downwards....
Paul Walbran

This thread was discussed between 27/02/2015 and 01/03/2015

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