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Front brake squeals

Discussion in 'Maintenance and Servicing' at netrider.net.au started by RedWings01, Feb 21, 2016.

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  1. Hey guys,

    So recently, my front brake has been squeaking more and more. I'm not sure exactly why and how to fix it. I looked at the brakes and it still had quite a lot of pad left. When I apply front brake at speed, the squeal is extremely minimal and cannot be heard when the bike is on. It pretty much just sounds like a normal squeak you get on brakes. Problem is, when I reverse the bike and turn the handle bars to the right, it squeaks so loud that everyone within 10m will notice it. Just imagine pulling out of a parking spot with a massive squeal while others look at you.....So I would love to fix it. It only ever squeals like this when I turn handle bars right and reverse. Nothing else.

    Any ideas? I was thinking taking the calliper apart, spraying brake cleaner on it when its taken apart and put it back together. Hopefully this will fix it. Any recommendations?

    Thanks.


     
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  2. Brake pads can get glazed so a light sanding will take that glaze off and stop the squealing. The fact that it occurs in reverse with the handlebars to the right tends to suggest an issue with the floating callipers. That model is a single disk on the right side (I think) check the calipers and disks move freely along the support bolts. Brake cleaner will help as a start anyway.
     
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  3. #3 RedWings01, Feb 21, 2016
    Last edited: Feb 21, 2016
    Ok, So I was thinking of taking the callipers off, taking out the brake pads, sanding the pads a little, spray with brake cleaner and clean as much of the brake dust as I can and then put it back all together. Hoping that should fix all the issues. Only started happening a few days after I bought the bike.

    EDIT: Just had a look, the metal on the back of the brake pads are rusted as hell. Maybe that might be the issue. Compared to the rear brake pads, they are completely rusted. Will prob buy some front brake pads online and switch them out.
     
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    • Agree Agree x 1
  4. I would just sand lightly. Or just pop them out and give them a few seconds rub against a bit of sandy concrete, like your neighbour's driveway... Do the back (backing plate) as well, but don't spray WD-40 or anything on it...

    You could also get a bit of emery paper or emery cloth, and lightly and evenly go around the disk. Don't over-do it, and do try and make it all the same, don't go ballistic on one spot. I wouldn't even bother with that the first time, just clean the pads up a little and put them back in.

    [edit] Disk brakes are prone to squeal a little. If they're squealing, they're probably working. When they stop squealing, that's when you worry...
     
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  5. ... as an afterthought... Some of the boys are chatting on another thread, about a pushbike with a disk brake. There's a little humor there, which is nice, but I hope no damn fool does try and put Mr Sheene on his brakes... My point, apply a little thought and common sense to any other answers you get here, people have been known to give out advice which will get you killed, because it was funny and any damn fool could see it was a joke... When I was a young bloke, I got a lot of advice from older riders, and I hate to say it, but more than half of what I was told was liable to get me killed if I simply believed it...
     
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  6. could be a build up of brake dust. try blowing some compressed air in there.
     
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  7. Yeah of course I'm not that stupid to believe stuff like that. I do have some sort of common sense. I understand what you mean by saying all brakes squeak but this is an extremely loud squeal that can be heard by people within 10m. Sucks when pulling out of a parking spot and having everyone stare at you.
     
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  8. If in doubt and you are not getting a solution on the forum,go to the local bike shop.One or two hundred dollars could be money well spent (y)
     
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  9. if you have 2 mates nearby, get them to lift the front of the bike and then spin the front wheel forwards and backwards.
    does it spin freely or does it drag?
    when you turn to the right, is there a difference in drag compared to turning left or straight?

    if it is dragging, could be the slides gummed up or lacking lube, or could be the piston not being retracted by the seal.
    could even be a bit of air in the system expanding when warm (if it does it more after sitting in the sun),

    a quick thing to try is push the piston back in a few mm, then pump back out with brake lever, and also move the caliper slides in and out a few times to see if it feels stiff or moves easily
    better to do after cleaning dust of outside of piston so you don't push dirt into the seal

    putting in new pads will push the piston back in too... again, clean piston first.

    probably worth replacing the brake fluid or at least bleeding properly (may as well keep doing that until fluid is clean tho).

    condition of the disc can also have an effect, is it flat? worn?

    as above, if in doubt, check with local shop.
     
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  10. They do need maintenance now and again. All disk brakes squeak a little now and again. I prefer emery for deglazing. the finer the better. It doesn't take much. The possibility of getting garnet bits in the pads from sandpaper has always concerned me and I think a good wet & dry emery paper is probably much a much better option. The bonding adhesive would be better, less possibility contaminating the pad with abrasives that are going to take it out on your disks. I wouldn't bother with deglazing unless the discs are annoyingly noisy. Have a look at them any way, there's many a rider realised the pad material is gorn! and it's the metal backing making the noise. Keep an eye on them.

    Dragging is a different thing. Changing pads or fluid won't generally fix brakes that drag. Yeah, they get dirty, the piston/cylinder interface somehow does not work correctly and somehow it just doesn't go back as it should. Maybe there is a dust seal or piston seal failure, water and or dirt has got in. Maybe it's starting to develop a bit of corrosion.

    This is a great area for the budding wannabe mechanical person to tackle- beyond oil changes and chain issues, to have a crack at. Best placed after valve clearance adjustment in the order of difficulty if the valves are not buckets and shims. It's not rocket science and does not require a lot of specialised tools. Brake calipers are close to the road, exposed to all the grot and easy to get to.

    Just remember, do not squeeze your brake lever with the wheel removed. You should be able to push the pads (and pistons) back without a lot of difficulty. If you can't, you may have a frozen piston finally succumbed to the chemical and mechanical forcers at work. Adventurous people will just pull it all apart (be prepared to purchase pistons and seals - frozen pistons are often damaged in removal if you get brutal) and put it all together again. There isn't really adjustment involved. Refilling and bleeding the system is the fiddly part. All a part of the learning, if that is what you want.
     
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  11. I had a problem with a really old bike with disk squeal and it came from the metal that touches the brake pad metal.
    It's hard to explain but it's like a metal shim which should have a slight layer of heat resistance puty on it which helps vibration which in turn can cause squealing.
    I brought some brake pad puty from the auto store put it between the shim and brake pad and bingo no more squeal.
     
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