WinchesterDave Posted June 12, 2014 Report Share Posted June 12, 2014 As the question Says, I got a new, good (to me) Trek hardtail MTB last year. It's been great and perfect for what I do, however the thing is, everytime I feather the rear brake (hydraulic disc) and put pressure down on the brake lever the loudest most unpleasant noise occurs and vibration goes all throughout the bike!! I hate using my rear brake but going down hill it's needed To control speed obviously but the noise and vibration is horrendous!! :s have no idea why that happens could someone give me advice or explanation as to why this is happening cheers. Dave Quote Link to comment Share on other sites More sharing options...
Rimfireboy Posted June 12, 2014 Report Share Posted June 12, 2014 Is the disc warped or calliper loose, or are the pads worn out? Quote Link to comment Share on other sites More sharing options...
Cyrus1988 Posted June 12, 2014 Report Share Posted June 12, 2014 Is the disc warped or calliper loose, or are the pads worn out? What he said. Also it could be the mounts that the calliper is attached to. If there out of line with the disc it'll make it squeak too. Quote Link to comment Share on other sites More sharing options...
Sir_Adam Posted June 12, 2014 Report Share Posted June 12, 2014 Failing that you could just have dirt dried onto the pads. Depending how many miles it's done it could be worth filing them down. That's what happened to mine when is been unable to use it for a while due to an accident. Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 12, 2014 Author Report Share Posted June 12, 2014 What do you mean by warped? I'll check the allignment of the calliper and then take the pads out and file them. Anything specific to file the pads down with? Thanks for the response guys. Quote Link to comment Share on other sites More sharing options...
Cannon Posted June 12, 2014 Report Share Posted June 12, 2014 The disc is probably not completely flat. Even a tiny bit of runout can cause the disc to make screeching noises. Are the brake pads loose or worn excessively? Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 12, 2014 Author Report Share Posted June 12, 2014 Ohhh! Tombe honest im not sure ive never taken them out:/ I will,do some YouTube research tonight and have a play tomorrow. Are they easy to remove and re fit? There seems to just be a metal bar type object holding them in im guessing you take this out? How do I kmow if the calliper is alligned? Quote Link to comment Share on other sites More sharing options...
halfbee Posted June 12, 2014 Report Share Posted June 12, 2014 (edited) Whip the pads out and clean them on a flat piece of wet and dry/emery cloth. Put the abrasive on a flat surface so you sand the pads flat. treks of a certain age have a bolt on disc adapter which can cause a harmonic vibration when the pads are grubby or the mount isn't 100 % clean and tight so it's worth unbolting it, cleaning the mating surfaces and putting it back nice and tight. Disc brake adaptor: http://www.westmichiganbike.com/images/library/large/tk_1_intl_discbrk_mount_12_m.jpg [\img] Edited June 12, 2014 by halfbee Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 12, 2014 Author Report Share Posted June 12, 2014 Thanks halfbee I'll clean and realign tomorrow Quote Link to comment Share on other sites More sharing options...
DannyNCC Posted June 13, 2014 Report Share Posted June 13, 2014 Has it got floating disc Quote Link to comment Share on other sites More sharing options...
Velocette Posted June 13, 2014 Report Share Posted June 13, 2014 Have a look at the pad material,,,,if its sintered metal try changing to organic ones. Also try changing the make of pad. I too had a hell of a noise on my Formula Oro brakes until I experimented with materials. Evan tried one sintered and one organic on the same caliper. The organic ones tend to be for normal dry weather use. Quote Link to comment Share on other sites More sharing options...
trickyh Posted June 13, 2014 Report Share Posted June 13, 2014 I had the same thing on a Hope front disc. Turned out the disc was warped. You can check it easily by removing the disc from the hub and laying it on a flat piece of glass. HTH! Quote Link to comment Share on other sites More sharing options...
Lord Geordie Posted June 13, 2014 Report Share Posted June 13, 2014 You couod try oiling it! Works on squeeky hinges JOKING of course! had a friend try it on his Cortina I find a lot of pushbikes squeal when applying the rear brake! I don't think ot's due to warped disks That would squeak intermitently normally but not when applying the brakes. I think it's most likely a contaminate on the brake pad surface! Try a bit of emery cloth on the pad surface! And clean the disk with meths etc! A medical alcohol wipe will work well too! It just removes grease and grime! Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 13, 2014 Author Report Share Posted June 13, 2014 (edited) Okay guys update; Took wheel off, then took the pads out, cleaned them On some light sandpaper which seemed To clean them up, got a meths type sunstance and cleaned the rotor which got off a bit of muck. Replaced the wheel Etc and went to realign calliper which I did after some patients haha! Anyway, took bike out for a Test ride up the road and the initial brake was; Vibration/noise gone... Distinct lack in stopping power... After a while stopping power slowly came Back and vibration/noise was not there! I thought I'd fixed it, but then a small sound was Coming back and then eventually the whole vibation and noise was back! Went back to the garage and the discs as you can imagine were rather on the hot side to touch... Let them cool down and went back out... Stopping power was fine noise had gone... You can guess what's coming.. Yes the vibration and noise came Back after a while of stop starting with the brakes, went back in and they were very hot. I repeated this another time and the same Thing happened, my conclusion is this horrible noise and vibration occurs when the rotor gets hot? Any suggestions? Dave. Ps thank you all for your helpful comments! Edited June 13, 2014 by WinchesterDave Quote Link to comment Share on other sites More sharing options...
brett1985 Posted June 13, 2014 Report Share Posted June 13, 2014 sounds like its time for a new disc matey.... i would imagine its possible that the disc is worn to a point that when it gets hot, it starts to deform and flex with the heat, causing the vibration. i could be wrong mind you.... how much is a new disc? Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 13, 2014 Author Report Share Posted June 13, 2014 Hrmmm I'd be a bit peed if I did need a new Disc, it's less than a year old and I've not don't any hardcore riding at all :s Quote Link to comment Share on other sites More sharing options...
Velocette Posted June 13, 2014 Report Share Posted June 13, 2014 Check that the pads are not dragging/binding then CHANGE THE MATERIAL. A disc would have to be turning blue before there is the slightest chance of it warping, Quote Link to comment Share on other sites More sharing options...
brett1985 Posted June 13, 2014 Report Share Posted June 13, 2014 Hrmmm I'd be a bit peed if I did need a new Disc, it's less than a year old and I've not don't any hardcore riding at all :s ahh, i see. probably not that then! is the bike still under any type of warranty at all? Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 13, 2014 Author Report Share Posted June 13, 2014 How do you mean Binding? Ermm I'm not sure it possibly might still be in warranty Quote Link to comment Share on other sites More sharing options...
Velocette Posted June 13, 2014 Report Share Posted June 13, 2014 Binding means that the pads are touching the disc when the brake is not applied.This is easily checked by spinning the wheel and watching to see how long it takes to slow down. If it comes to a sudden and noisy stop then the pads are binding. This can be caused by a sticky piston in the caliper. Take the pads out and physically force the pistons fully in with something like a plastic tyre lever which won't damage anything. then re=fit the pads and try the spin test again. if there is no noise then apply the brake and watch/listen again. Sudden stop and or noise suggests that the pistons need looking at and cleaning together with new seals to be on the safe side. Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 14, 2014 Author Report Share Posted June 14, 2014 Oh I Don't think that's happening, I realigned The caliper and When the wheel moves It doesn't touch the pads Quote Link to comment Share on other sites More sharing options...
bear-uk Posted June 15, 2014 Report Share Posted June 15, 2014 Fit new pads. Find a big hill. Fly down dragging brakes so they get red hot. Take water bottle off bike and drench brakes. Sorted. Quote Link to comment Share on other sites More sharing options...
Cannon Posted June 15, 2014 Report Share Posted June 15, 2014 Thats a good way to warp the disc. How would that fix the problem bear? Quote Link to comment Share on other sites More sharing options...
WinchesterDave Posted June 16, 2014 Author Report Share Posted June 16, 2014 Warp being mis shape the rotors Im Guessing? Quote Link to comment Share on other sites More sharing options...
Cannon Posted June 16, 2014 Report Share Posted June 16, 2014 Yes indeed. If you get them red hot and throw cool water over them it will probably distort them, causing even more issues. Are the brake pads secured with a single nut? Pics would be helpful if you could upload some? Quote Link to comment Share on other sites More sharing options...
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