Ian C Posted May 30, 2004 Share Posted May 30, 2004 I've warped about four sets of UK discs, so it does happen. You can't see it with the naked eye, you have to use a set of calipers (not brake ones haha) and measure the disc thickness four times at four equidistant points around it's circumference. Anything more than about a tenth of a millimetre is warped and you need to swap them. Warping usually occurs when the car is stationary, bizarrely enough, because you've murdered the brakes and they have a lot of heat in them. Then you park up and the bit of disc under the pad cools down a lot slower than the rest of the disc, so one quarter of it ends up warped. Each time I've done it I've measured the disk thickness (disk 'runout') as I described above and only one quarter of the disk is wider than the rest. You can hear it on disks that have gotten wet and have some surface rust on as well, when you drive at walking pace with the window down - the wider bit catches on the brake pads and makes a noise. Warped disks will manifest themselves at high speed braking and can even, when badly warped, cause a vibration at high speeds due to the uneven mass osciallating. Hope that answers a few "how can I warp UK disks" questions. As for driving the car with a known-to-be-buggered brake system, I'll remain silent -Ian Quote Link to comment Share on other sites More sharing options...
Whitesupraboy2 Posted May 30, 2004 Share Posted May 30, 2004 Originally posted by Ian C As for driving the car with a known-to-be-buggered brake system, I'll remain silent -Ian Remain silent yes....but point recieved Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted May 30, 2004 Share Posted May 30, 2004 Originally posted by Ian C Warping usually occurs when the car is stationary, bizarrely enough, because you've murdered the brakes and they have a lot of heat in them. Then you park up and the bit of disc under the pad cools down a lot slower than the rest of the disc, so one quarter of it ends up warped. -Ian That would be the hot-spotting of the discs I was on about before. See I am not just an ugly face. Quote Link to comment Share on other sites More sharing options...
Syed Shah Posted May 30, 2004 Share Posted May 30, 2004 Originally posted by Ian C I've warped about four sets of UK discs, so it does happen. Warping usually occurs when the car is stationary, bizarrely enough, because you've murdered the brakes and they have a lot of heat in them. Then you park up and the bit of disc under the pad cools down a lot slower than the rest of the disc, so one quarter of it ends up warped. -Ian Exactly why I said they should not warp on the road 'given adequate cooling off'. A bit of gentle driving before parking up is cheap insurance for both disks and turbos. Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted May 30, 2004 Share Posted May 30, 2004 Originally posted by Syed Shah Exactly why I said they should not warp on the road 'given adequate cooling off'. A bit of gentle driving before parking up is cheap insurance for both disks and turbos. And not sitting on hills after you just stopped with your foot on the brake pedal. Especially bad if you just stopped from motorway speeds. Use your handbrake thats what its there for. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 30, 2004 Share Posted May 30, 2004 Originally posted by Syed Shah Exactly why I said they should not warp on the road 'given adequate cooling off'. A bit of gentle driving before parking up is cheap insurance for both disks and turbos. Yeah, my trouble was that I "tested" the brakes one quiet night on the slip road off my exit from the A11, 140mph to zero in half the slip road length. Great, except the five minutes it took to get home after that didn't actually let the brakes cool enough. I knew it might warp them but couldn't be arsed to get the car back out of the garage and drive around a bit -Ian Quote Link to comment Share on other sites More sharing options...
Paul Laing Posted May 31, 2004 Author Share Posted May 31, 2004 New caliper getting ordered tomorrow, along with some Brembo 20 groove disks Quote Link to comment Share on other sites More sharing options...
Suprash Posted May 31, 2004 Share Posted May 31, 2004 For what its worth I have also warped a set of UK's in one stop, 120 to zero....... Quote Link to comment Share on other sites More sharing options...
Paul Laing Posted May 31, 2004 Author Share Posted May 31, 2004 Crikey, best get these Brembo's then. Anyone got Brembo disks? Are they decent? they have 20 grooves in them Quote Link to comment Share on other sites More sharing options...
Gordon F Posted May 31, 2004 Share Posted May 31, 2004 Originally posted by dangerous brain at least have thread inserts put in them so that you know for sure the pipe won't come out. A decent engineering shop will be able to fit an insert such as a Wurth Time Sert, and face off the area where the copper washer on the brake pipe sits. A safe, proper repair, and much cheaper than a new caliper Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted May 31, 2004 Share Posted May 31, 2004 I must admit to being puzzled by this warping issue. I've lapped Silverstone GP circuit, braking on the ABS and not had a problem. I guess the lack of back-plates may make a difference, but apart from that I've no extra cooling (apart from a slowing down lap). I'm not braking to a stand-still of course. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 31, 2004 Share Posted May 31, 2004 It's the cooling down lap John, it lets all the heat in the brakes dissipate evenly. It's not the physical act of stopping that warps 'em, it's parking up afterwards while they are still hot enough to vapourise water. -Ian Quote Link to comment Share on other sites More sharing options...
Paul Laing Posted May 31, 2004 Author Share Posted May 31, 2004 I never stop all of a sudden after a good thrashing of my car, does anyone??? I allways have to drive home, going through an estate so that gives the disks time to cool. Can't believe people warp disks like, i hope my new disks are good, Brembo ones usually are Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted June 1, 2004 Share Posted June 1, 2004 Ian, particularly as on a track like Silverstone speed doesn't drop below 60mph or so even on the slow bits, so plenty of air movement to take away the heat. I'm sure the lack of back-plates helps and I am looking at the practicality of adding some ducting to the fronts. Sorry Paul, thread hijack. Let me know when you get the wheel studs. Quote Link to comment Share on other sites More sharing options...
Whitesupraboy2 Posted January 28, 2008 Share Posted January 28, 2008 the memories a search can bring up Quote Link to comment Share on other sites More sharing options...
Alex Posted January 28, 2008 Share Posted January 28, 2008 Hi I'm driving a car with brake fluid peeing out, is it safe? Quote Link to comment Share on other sites More sharing options...
Ian R Posted January 28, 2008 Share Posted January 28, 2008 the memories a search can bring up Can you dig out the Where are my turbo's thread ?? I loved that one Quote Link to comment Share on other sites More sharing options...
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