Miller350z Posted April 6, 2017 Share Posted April 6, 2017 Does anyone know why my car would be vibrating under braking? The rear of the car vibrated really badly and violently under braking last year around August time. So i changed the rear discs for mtec dimpled and grooved discs and ebc red stuff pads. The vibration stopped immediately and was nice and stable with no vibration. The car has only done about 2500 miles since putting the new discs and pads on and I can feel vibration/judder through the pedal again. Never through the steering just the pedal. So are my rear discs warped again? How could they be? And if they are would mtec replace them as surely they shouldn't be that bad after only a few months/miles Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
The Bounty Bar Kid Posted April 6, 2017 Share Posted April 6, 2017 1. Who fitted them? Was it done correctly? 2. Have deposits built up on the discs. Usually reversing and then braking to remove them can help. Have to do it a few times to get rid of it. Quote Link to comment Share on other sites More sharing options...
Miller350z Posted April 6, 2017 Author Share Posted April 6, 2017 I fitted them. Yeah they were all done right. There's not really a lot of build up really. I'm going to check the run out, clean the disc and have a few hard braking sessions. Just to eliminate the brake discs from being the problem. I thought it could possibly be the discs but as they're fairly new I was wondering if anyone had encountered the same sort of problem and found the issue to be something else Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
Aashenfox Posted April 6, 2017 Share Posted April 6, 2017 Are your backing plates still in place? Sometimes people remove the backing plates which are there to protect the inside pads and disc surface from the road rash they get if left unprotected. Particularly the inner pad on cars with missing plates gets into a terrible state quickly, which then affects the surface of the disc and can even cause deformation of the disc. Just a thought. Quote Link to comment Share on other sites More sharing options...
Miller350z Posted April 6, 2017 Author Share Posted April 6, 2017 Hi, Yeah the plates are all still in place. It may well be a build up of dirt. I haven't really used them properly in a while as I've just been doing the 30mph drive to work so they haven't had much serious use. I'll give the dics a clean up this afternoon and check the run out. Hopefully I'll get it sorted Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
colesl4w Posted April 6, 2017 Share Posted April 6, 2017 You could try doing the procedure which involves braking from 60 -> 20 hard, 8-10 times in quick succession. People have had a lot of success with that. I'm due to try that but need to find a good stretch of road to do it on! Quote Link to comment Share on other sites More sharing options...
Aashenfox Posted April 6, 2017 Share Posted April 6, 2017 Do a few hard reverse brakes as well. Quote Link to comment Share on other sites More sharing options...
RobPhoboS Posted April 6, 2017 Share Posted April 6, 2017 They don't warp! (unless you got them from lidl ) Just go and do a bedding in process but about 15-20x, not just 10x slow downs. My friend thought his e92 m3 discs were warped on tue, getting crazy vibration through the car when braking. Did some bedding in, and part way through the track day at Spa yesterday they had gone back to normal. (just to prove a point) As long as the hubs were clean and you torqued everything up correctly, it'll be deposits from the pads. Worth checking of course Possibly because you got them hot and left the hand brake on/foot on pedal without letting them cool down. 1 Quote Link to comment Share on other sites More sharing options...
Aashenfox Posted April 6, 2017 Share Posted April 6, 2017 Possibly because you got them hot and left the hand brake on/foot on pedal without letting them cool down. That's good thinking right there. Quote Link to comment Share on other sites More sharing options...
colesl4w Posted April 6, 2017 Share Posted April 6, 2017 Best result if that is the case! A good free fix is always nice. 1 Quote Link to comment Share on other sites More sharing options...
Stutopia Posted April 6, 2017 Share Posted April 6, 2017 Can someone explain the reverse braking please? Isn't the brake bias the same whether you're going forward or backwards? Or is it the weight transfer you're after? Ta Quote Link to comment Share on other sites More sharing options...
Olly350z Posted April 6, 2017 Share Posted April 6, 2017 Another vote for redoing the braking in procedure, had this a while ago! A good late night run up and down duel carriageway cured it, no more vibrations or clonks Quote Link to comment Share on other sites More sharing options...
Aashenfox Posted April 6, 2017 Share Posted April 6, 2017 (edited) Can someone explain the reverse braking please? Isn't the brake bias the same whether you're going forward or backwards? Or is it the weight transfer you're after? Ta It's more a case of rubbing the pad against the disc in the opposite direction to the one that it's most used to. Especially if you have dimpled or grooved discs, it can clean the pad quite effectively I'm told. second hand info, I won't deny it, I've never used the procedure effectively myself (never needed to, to date), probably cos I change cars more often than brake pads! Edited April 6, 2017 by Aashenfox Quote Link to comment Share on other sites More sharing options...
Stutopia Posted April 6, 2017 Share Posted April 6, 2017 Can someone explain the reverse braking please? Isn't the brake bias the same whether you're going forward or backwards? Or is it the weight transfer you're after? Ta It's more a case of rubbing the pad against the disc in the opposite direction to the one that it's most used to. Especially if you have dimpled or grooved discs, it can clean the pad quite effectively I'm told. second hand info, I won't deny it, I've never used the procedure effectively myself (never needed to, to date), probably cos I change cars more often than brake pads! Makes sense, ta Quote Link to comment Share on other sites More sharing options...
colesl4w Posted April 6, 2017 Share Posted April 6, 2017 I gave this a go last night as I have the same issue. Problem is that you need to do it late at night when the roads are empty - my exhaust was making an absolute racket lol, which usually I'm a fan of but I'm sure it had people wondering wtf was going on, and I saw 3 police cars around the same time. Need to find a better spot! 1 Quote Link to comment Share on other sites More sharing options...
zumpitu Posted April 6, 2017 Share Posted April 6, 2017 (edited) I had this problem on My car all the time I think is also a lot doing with the fitting, I think is always needed to check if the disk is really on the right position and has no "waving ".. .needs to be checked with the " Test Indicator" .. I mean this thinks here Edited April 6, 2017 by zumpitu Quote Link to comment Share on other sites More sharing options...
Miller350z Posted April 6, 2017 Author Share Posted April 6, 2017 Like this one. Did this today but it was really hard to tell as the slightest bit of pressure on the disc and the dial went mad. I did notice that there was about 5mm of pad gunk in some of the grooves so I'll give the hard braking thing a go. I did take it out afterwards and did try the hard braking but only about 5 times. When I pushed them really hard (like emergency stop) I couldn't feel it as much. So I'll be giving this a go. Like was previously said this solution is free. May possibly be having a quick go around Caldwell in a few weeks. Nothing special just a 20 mins session but wanted good brakes for that! Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
RobPhoboS Posted April 7, 2017 Share Posted April 7, 2017 Watch this... Read this... http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths It's free and easy to do, so always worth doing, use your common sense of course and don't bring the car to a stop or you'll be doing the same thing over again. Quote Link to comment Share on other sites More sharing options...
Toon Chris Posted April 7, 2017 Share Posted April 7, 2017 (edited) Possibly because you got them hot and left the hand brake on/foot on pedal without letting them cool down. That's good thinking right there. Maybe but rear discs don't get all that hot unless you have been giving it some beans, which is unlikely on 30mph tootles to work. And the handbrake is shoe-based so that won't be the issue. Edited April 7, 2017 by Toon Chris Quote Link to comment Share on other sites More sharing options...
RobPhoboS Posted April 7, 2017 Share Posted April 7, 2017 Possibly because you got them hot and left the hand brake on/foot on pedal without letting them cool down. That's good thinking right there. Maybe but rear discs don't get all that hot unless you have been giving it some beans, which is unlikely on 30mph tootles to work. And the handbrake is shoe-based so that won't be the issue. I used the word 'possibly' as he didn't state how he'd been driving. Anyway, he should try out a proper bedding in process first Quote Link to comment Share on other sites More sharing options...
LarryR Posted April 14, 2017 Share Posted April 14, 2017 I have been told it can be a calliper that is sticking! I have the same problem I have taken off the wheels and the driver side rear is worn a lot more than the passenger side so I have new pads and discs to go on and a new brembo calliper. Quote Link to comment Share on other sites More sharing options...
Ebized Posted April 14, 2017 Share Posted April 14, 2017 Im sure Marcus would get to the bottom of what is causing your problem: http://www.discskimmers.com OK, distance may be an issue but he travels and maybe you could sort something out. Quote Link to comment Share on other sites More sharing options...
Jay Kay Posted April 14, 2017 Share Posted April 14, 2017 Are you sure its the rears and not the fronts? Quote Link to comment Share on other sites More sharing options...
Miller350z Posted April 23, 2017 Author Share Posted April 23, 2017 Thanks for all the replies. A quick update in this. I had the clicking axle to out today so had a look at the rear discs whilst I was at it. The front side of the near side rear disc looked ok but on the rear there was a fair bit of pad deposits. The groove in the pad was also full of pad gunk. So I cleaned them up by picking the deposits out and giving the disc a good clean. Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
Miller350z Posted April 23, 2017 Author Share Posted April 23, 2017 So I then went to the off side and that didn't look that bad. It did have some deposits from the pad but not as much. So cleaned it up as well. However when I was looking at the disc the outer part looked thinner then the inner. So I measured it and it's 1mm thinner. What do people think of this? Aren't both sides supposed to be the same thickness? It's like the outer it a softer metal, it's warped and caused my problems. Sent from my SM-G930F using Tapatalk Quote Link to comment Share on other sites More sharing options...
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