warped disks, can they be saved ?

Soldato
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I bought a 2nd hand set of calipers/disks/pads off ebay but the disks were warped, the garage I used sent them to a local guy to have them machined, but they still vibrated badly under braking.

I replaced them with a set of genuine Ford disks and after a period of time they also warped.
So I then decided to replace disks and pads with brand new
i went for these discs (grooved only)
https://www.mtecbrakes.com/mtec1386.html
with mintex m1144 pads

fitted in Dec/Jan by Feb the disks had warped again.


Starting to get a bit fed up with the whole situation in honesty.
I spoke with the garage and he said that he has never had much luck with getting disks machined.

I can't understand why though, to my mind if a disk is machined flat then it should be no different than fitting a brand new disk.

I am not keen on spending £100 on yet another set of disks if there is anywhere that can machine the ones I have and get them to not vibrate under braking.

thoughts ?
 
Soldato
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Have you checked that the problem isn't the result of a sticking caliper piston/guide pin?

A disc is a relatively simple affair. You get it skimmed, it's level, job done – you can't not have 'much luck' with that; it just works. That's what I'd do. :)

You're not warping the metal, after all – it's just debris from the pad being fusing with/glazing the surface of the disc unevenly that causes the issue (or deformations in the casting causing an uneven surface). Quick skim and it should be good to go.
 
Soldato
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It's warped from overheating. You might be able to get the surface flat but the metal itself is still warped so it will never be quite right.
 
Soldato
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It's warped from overheating. You might be able to get the surface flat but the metal itself is still warped so it will never be quite right.

That's not what happens in any road car, even if it's tracked (nor does it happen in race cars).

As an aside, MassiveJim, one way you can potentially fix this is to go out and do a series of full-power emergency stops. I've cleared 'warped discs' this way in both my own and friends' cars.
 
Soldato
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I seriously doubt you've genuinely warped that many discs. More than likely you've not warped any, it's actually very rare.

In all likelihood it's a result of what Lashout describes but it may also be worth getting the fittings checked thoroughly, make sure it's not just a bolt or something routinely working loose.
 
Soldato
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That's not what happens in any road car, even if it's tracked (nor does it happen in race cars).

As an aside, MassiveJim, one way you can potentially fix this is to go out and do a series of full-power emergency stops. I've cleared 'warped discs' this way in both my own and friends' cars.
I did try this with the current disks and it seemed marginally better for a few miles but now is worse than ever with noticeable vibration at speeds as low as 20/30mph

I got up to about 80/90mph and braked down to 30/40ish about 4 /5 times in a row

I did wonder if it could be caliper related as they were bought second hand off ebay.
the only thing is that my old disks also warped with my original calipers (upgraded my ST220 calipers to ones from an ST225)
 
Soldato
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In my experience the main cause of warped disks, tends to be when poeple just chuck the pads back in the caliper with out cleaning the pad clip holder and where the clip sits in the caliper.
 
Soldato
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Don't think this helps in anyway but I kept the old disks and they look fine

https://imgur.com/gallery/fxpAY2b

Probably what is causing this is the last 15 minutes of my journey home is a good old b road. So when it's clear I give it the beans.

I have handed my notice in on current job though so that drive will come to an end soon
 
Don
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Worth getting a set of Vernier callipers and measuring the thickness at multiple points around them. Suspect they probably aren't warped at all.

Warped discs seems to be a term thrown around as a catchall for non specific brake problems
 
Soldato
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I just use a small wire brush or wheel to clean up the stainless clip, and then a small needle file to polish up where the clip sits. Just to get rid of the grot.
 
Soldato
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Ecp have 50% off for the next 6 days so I could get a new set of either pagid, brembo or mintex disks for £75.

But it seems that warped disks may not be the problem here.
If the caliper is sticking and I get it freed up, I assume a heavy breaking session will clean the disk up and should alleviate the problem?
 
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