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warped disks, can they be saved ?

Discussion in 'Motors' started by MassiveJim, May 15, 2019.

  1. MassiveJim

    Wise Guy

    Joined: Feb 22, 2014

    Posts: 1,638

    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 ?
     
  2. Lashout_UK

    Capodecina

    Joined: Mar 2, 2004

    Posts: 11,641

    Location: SE England

    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.
     
  3. Nasher

    Capodecina

    Joined: Nov 22, 2006

    Posts: 11,542

    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.
     
  4. Lashout_UK

    Capodecina

    Joined: Mar 2, 2004

    Posts: 11,641

    Location: SE England

    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.
     
  5. Kenai

    Capodecina

    Joined: Apr 5, 2009

    Posts: 17,559

    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.
     
  6. Diddums

    Capodecina

    Joined: Oct 24, 2012

    Posts: 17,409

    Location: London

    Yeah you're gonna need to explain how you came to this conclusion.
     
  7. MassiveJim

    Wise Guy

    Joined: Feb 22, 2014

    Posts: 1,638

    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)
     
  8. Mal X

    Sgarrista

    Joined: Jun 25, 2009

    Posts: 7,663

    ha ha, he's gone quiet.
     
  9. Nasher

    Capodecina

    Joined: Nov 22, 2006

    Posts: 11,542

    Metal has a grain...

    If it's warped once and you skim the surface, it will warp again.
     
  10. Armageus

    Don

    Joined: May 19, 2012

    Posts: 9,564

    Location: Spalding, Lincolnshire

    ??? What rattled you?

    Haven't you got a motorway to slalom along?
     
  11. vanpeebles

    Soldato

    Joined: Aug 22, 2004

    Posts: 5,254

    Location: County Durham

    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.
     
  12. MassiveJim

    Wise Guy

    Joined: Feb 22, 2014

    Posts: 1,638

    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
     
  13. vanpeebles

    Soldato

    Joined: Aug 22, 2004

    Posts: 5,254

    Location: County Durham

    The pad has been grabbing on the back of those, points to sticky caliper/stuck pad.
     
  14. Armageus

    Don

    Joined: May 19, 2012

    Posts: 9,564

    Location: Spalding, Lincolnshire

    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
     
  15. tl45

    Hitman

    Joined: May 26, 2014

    Posts: 613

    Location: Warrington

    If any of this leads to a new set of ST225 discs being needed I happen to have a set that I no longer need
     
  16. kindai

    Soldato

    Joined: Aug 9, 2013

    Posts: 6,142

    Location: Bromsgrove

    Quite, the temperatures and pressures needed to genuinely warp a disc are just inconceivable in most road cars. More likely an issue with the pads or calipers.
     
  17. BUDFORCE

    Hitman

    Joined: May 3, 2012

    Posts: 880

    I'm guilty of this. I have learned from this post, thank you.
     
  18. vanpeebles

    Soldato

    Joined: Aug 22, 2004

    Posts: 5,254

    Location: County Durham

    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.
     
  19. MassiveJim

    Wise Guy

    Joined: Feb 22, 2014

    Posts: 1,638

    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?
     
  20. vanpeebles

    Soldato

    Joined: Aug 22, 2004

    Posts: 5,254

    Location: County Durham

    I’d go new pads and discs, and make sure everything is nice and clean.