Strudul Posted January 3, 2017 Share Posted January 3, 2017 Turns out I've got some judder under heavy breaking... Took the Z to Halfords for a free brake test (what's the worst that could happen), while I hid in the boot: They came back and said they didn't notice any problems... However, from watching the vid, it looks like there is some variation on the left dial that they didn't pick up on. Should that be cause for concern? Turns out they also tested the rears on the rolling road, so now I'm worrying about LSD damage. Gonna try jack it up and check for disc surface variation tomorrow. Quote Link to comment Share on other sites More sharing options...
GMballistic Posted January 3, 2017 Share Posted January 3, 2017 Moved to the brakes sub section for you. You say it judders under heavy braking, ...has this started just recently after some spirited driving and heavy braking? or do you think it was happening already but you've only just found out after having to do some heavy braking? Are they new discs/pads fitted or older ones? Just trying to narrow down what may be causing it like improper brake disc fitting (dirt on hub when new disc fitted, uneven run out or incorrect bed in procedure), distorted disc (warped ~ pretty unlikely on todays vented discs) etc etc. Some good info here in this PDF for you: http://www.brakeworld.co.uk/pdf/tb1.pdf Quote Link to comment Share on other sites More sharing options...
Rob350 Posted January 3, 2017 Share Posted January 3, 2017 Nice to see he's enjoying the exhaust at the end of the vid lol Quote Link to comment Share on other sites More sharing options...
GMballistic Posted January 3, 2017 Share Posted January 3, 2017 Nice to see he's enjoying the exhaust at the end of the vid lol I didn't watch that far on the video, ...jeeze I wouldn't be happy with that guy revving my car that hard whilst stationary and probably not warmed up properly. Well that's Halfords for you I guess. Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 3, 2017 Author Share Posted January 3, 2017 (edited) Still posting everything in the wrong sections... One day... I very rarely touch my brakes at all, so it's new to me, but could have been there ever since I bought it. Only noticed it at all after Spoons pointed it out to me This could be part of the problem, and until recently I sometimes sit at the lights with my foot on the brake (never knew any better). Not sure when the discs were last changed, but according to Halfrauds they're at 29.1 and 29.2mm (out of 30mm new, and 28mm being the min). Pads were changed 1 year / 9000 miles ago. I'm assuming / hoping that it's just pad transfer build up or something causing an uneven surface rather than warping. Edited January 3, 2017 by Strudul Quote Link to comment Share on other sites More sharing options...
Jetpilot Posted January 3, 2017 Share Posted January 3, 2017 (edited) Follow a pad bedding in process, your choice which pad manufacturers recommended process you follow and if its still there you probably have a warped disc, get them skimmed. Edited January 3, 2017 by Jetpilot Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 3, 2017 Author Share Posted January 3, 2017 Follow a pad bedding in process, your choice which pad manufacturers recommended process you follow and if its still there you probably have a warped disc, get them skimmed. The intense ones would be best I guess. Not the ones which say only to do light braking for 500 miles Quote Link to comment Share on other sites More sharing options...
wez370 Posted January 3, 2017 Share Posted January 3, 2017 After watching that i'm surprised I didn't hear about a man from halfords head been caved in with a spanner. Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 3, 2017 Author Share Posted January 3, 2017 After watching that i'm surprised I didn't hear about a man from halfords head been caved in with a spanner. Didn't get to watch it until I got home unfortunately Quote Link to comment Share on other sites More sharing options...
Olly350z Posted January 3, 2017 Share Posted January 3, 2017 I'll waste his ****ing petrol... then proceeds to near bounce of the limiter... Id ve showing that video to his boss personally. Would go scatty if I caught someone driving mine like that... Id start with pad transference, as thats what mine turned out to be. I also took apart the pads and disks and gave everything a good clean, worked a treat Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 3, 2017 Author Share Posted January 3, 2017 I'll waste his ****ing petrol... then proceeds to near bounce of the limiter... Id ve showing that video to his boss personally. Would go scatty if I caught someone driving mine like that... Id start with pad transference, as thats what mine turned out to be. I also took apart the pads and disks and gave everything a good clean, worked a treat I'm not particularly chuffed about it, but I'm pretty sure he was revving at his boss, and nothing would come from it unless I really kicked up a fuss. Besides, I'm sure it's probably been abused in much the same way for the past 10 years and a little rev isn't the end of the world. That being said, if it blows up this week I'll be writing some very strongly worded letters. Quote Link to comment Share on other sites More sharing options...
Rob332 Posted January 4, 2017 Share Posted January 4, 2017 Did you get a printout to show the figures ? And is that the Halfords in Huddersfield? Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 4, 2017 Author Share Posted January 4, 2017 Did you get a printout to show the figures ? And is that the Halfords in Huddersfield? Nope, they only noted down tread depth and disc thickness. As you can see from the vid, they didn't record any data from the rolling road, they just looked at the dials and said it looks fine. Halfords in Wakefield. Quote Link to comment Share on other sites More sharing options...
Justthejedi Posted January 4, 2017 Share Posted January 4, 2017 I had all my discs skimmed and it cured my juddering brakes. The hotter they got the worse the judder, in particular the rears which had corrosion on the inside of the discs. Take your car to Marcus @ Disc skimmers, he'll sort it for you. He's on the forum. He cured mine. Quote Link to comment Share on other sites More sharing options...
davey_83 Posted January 4, 2017 Share Posted January 4, 2017 The road test video would have been fun eek Quote Link to comment Share on other sites More sharing options...
ricochet Posted January 4, 2017 Share Posted January 4, 2017 (edited) Bought my Z, my day car is a Mondeo, so I thought juddering on braking was was a powerfull car characteristic ....... took it to a local man for something else who said .. ' your front discs are wrecked o the inside' they looked fine on the outside. !! EBC turbo blades + yellowstuffpads sortred it. jc Edited January 4, 2017 by ricochet Quote Link to comment Share on other sites More sharing options...
Rob332 Posted January 5, 2017 Share Posted January 5, 2017 (edited) Did you get a printout to show the figures ? And is that the Halfords in Huddersfield? Nope, they only noted down tread depth and disc thickness. As you can see from the vid, they didn't record any data from the rolling road, they just looked at the dials and said it looks fine. Halfords in Wakefield. He hasn't done a full RBT. Looks like he has only checked the efficiency. Probably why it was free. He should have really done a fluctuation check by holding the pedal at a steady pressure. This checks for fluctuation of braking effort. A printout would have highlighted any imbalance also. Anything around 30% would need looking into. Best bet mate, if you are not mechanically minded would be to take the car to a decent garage for them to whip the wheels off and have a look at the condition of your brakes. Before I became an insurance engineer, I was a mechanic for 8 years and I wouldn't trust anyone from Halfords to hold a sponge, never mind a spanner. If they have one, you can ask them to do a full roller brake test and get a printout. if you are concerned about damaging your diff then ask them to just road test it. They will notice anything unusual. Hope this helps Edited January 5, 2017 by Rob332 Quote Link to comment Share on other sites More sharing options...
docwra Posted January 5, 2017 Share Posted January 5, 2017 STOP! Will people please stop referring to "warped discs", they dont exist ......... CARRY ON!! Quote Link to comment Share on other sites More sharing options...
Ebized Posted January 5, 2017 Share Posted January 5, 2017 STOP! Will people please stop referring to "warped discs", they dont exist ......... CARRY ON!! 1 Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 5, 2017 Author Share Posted January 5, 2017 He hasn't done a full RBT. Looks like he has only checked the efficiency. Probably why it was free. He should have really done a fluctuation check by holding the pedal at a steady pressure. This checks for fluctuation of braking effort. A printout would have highlighted any imbalance also. Anything around 30% would need looking into. Best bet mate, if you are not mechanically minded would be to take the car to a decent garage for them to whip the wheels off and have a look at the condition of your brakes. Before I became an insurance engineer, I was a mechanic for 8 years and I wouldn't trust anyone from Halfords to hold a sponge, never mind a spanner. If they have one, you can ask them to do a full roller brake test and get a printout. if you are concerned about damaging your diff then ask them to just road test it. They will notice anything unusual. Hope this helps Isn't a fluctuation check what was happening at 1:15 onward? Seemed to be holding it steady, needle on the right was still, but the left one was wavering. Happy to have a crack at checking them myself, though I don't have the best tools for doing it properly. Should be able to spin the discs and see if there are any variations in thickness etc. Would it be best to try re-bed them first and if that doesn't solve it then take them off and check them? Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 5, 2017 Author Share Posted January 5, 2017 Gonna try going from 60-10-60 and so on between these 2 roundabouts tonight and see if it resolves it After repeating 10 or so times, should I just cruise to a stop put the handbrake on for 30 mins or so to let them cool? Quote Link to comment Share on other sites More sharing options...
Rob332 Posted January 6, 2017 Share Posted January 6, 2017 He hasn't done a full RBT. Looks like he has only checked the efficiency. Probably why it was free. He should have really done a fluctuation check by holding the pedal at a steady pressure. This checks for fluctuation of braking effort. A printout would have highlighted any imbalance also. Anything around 30% would need looking into. Best bet mate, if you are not mechanically minded would be to take the car to a decent garage for them to whip the wheels off and have a look at the condition of your brakes. Before I became an insurance engineer, I was a mechanic for 8 years and I wouldn't trust anyone from Halfords to hold a sponge, never mind a spanner. If they have one, you can ask them to do a full roller brake test and get a printout. if you are concerned about damaging your diff then ask them to just road test it. They will notice anything unusual. Hope this helps Isn't a fluctuation check what was happening at 1:15 onward? Seemed to be holding it steady, needle on the right was still, but the left one was wavering. Happy to have a crack at checking them myself, though I don't have the best tools for doing it properly. Should be able to spin the discs and see if there are any variations in thickness etc. Would it be best to try re-bed them first and if that doesn't solve it then take them off and check them? It's worth a try. If no joy, when the wheels are off run your fingers along the surface of the disk top to bottom checking for pad transfer which would cause an uneven surface. Skimming a layer off the disc would remove this, but if the discs are worn anyway and there is a large lip I would just replace them with a good brand and a good brand of pads. It may be the case that the previous owner has fitted crappy cheap pads and these have caused your issue by transferring material on the discs. Treat yourself and upgrade to some dba t2s and hawk pads. Quote Link to comment Share on other sites More sharing options...
Kieran O'Quick Posted January 6, 2017 Share Posted January 6, 2017 After repeating 10 or so times, should I just cruise to a stop put the handbrake on for 30 mins or so to let them cool? Eh, generally not good form to put the handbrake on when the brakes are hot... ... can cause pad transfer. Leading to brake judder. Quote Link to comment Share on other sites More sharing options...
Strudul Posted January 6, 2017 Author Share Posted January 6, 2017 (edited) Bailed yesterday as it was rather icy. Weather is much warmer tonight, so will have another bash. Skimming a layer off the disc would remove this, but if the discs are worn anyway and there is a large lip I would just replace them with a good brand and a good brand of pads. It may be the case that the previous owner has fitted crappy cheap pads and these have caused your issue by transferring material on the discs. I say there is a large lip, but everything is relative. As they are 30mm new, and only down to 29mm now, the lip can't be more than 1mm? Eh, generally not good form to put the handbrake on when the brakes are hot... ... can cause pad transfer. Leading to brake judder. Just gotta drive about and try not to touch them then? Or try find a really flat area to sit without brakes or handbrake on? Edited January 6, 2017 by Strudul Quote Link to comment Share on other sites More sharing options...
Kieran O'Quick Posted January 7, 2017 Share Posted January 7, 2017 Yes, cruise around a bit to let them cool. Then park-up in gear. It's generally recommended to do that on trackdays too. Also, cooling down on the move is better than parking and cooling because that can actually boil your fluid and make it worse - (hot components near brake hoses with no air passing around). Quote Link to comment Share on other sites More sharing options...
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