Author Topic: Front Wheel Disc Brake Noise ! (Read 6877 times)

singhg5 · **on:** November 23, 2010, 10:51:58 pm

My bike has been making 'kTak' 'kTak' noises randomly, unrelated to speed, unaffected by bumps. It was coming from the front of the bike - riding slow or riding fast did not matter it just popped off and on. A bit distrubing. I looked for any loose nut/ bolts. The bike on center stand, rotated the front wheel no noise then. Though the wheel did not turn as freely as I would like. I cleaned the brake disc, the wheel then rotated fine. Went for a ride, again the same 'kTak' here and there.

Opened the brake caliper and found that there was a gap between the back side of brake pad and bottom piston (see picture below). The pad was not jammed. When moved by hand, it hit the piston and made the same 'kTak' sound I had heard during riding. I cleaned caliper, brake pads, pins and spring and put it back together. Went for a ride and the noise is back again.

Any thoughts or experiences with this kind of problem ?

prof_stack · **Reply #1 on:** November 23, 2010, 11:09:12 pm

Is your speedo cable securely affixed to the wheel?

singhg5 · **Reply #2 on:** November 23, 2010, 11:15:37 pm

Quote from: prof_stack on November 23, 2010, 11:09:12 pm

Is your speedo cable securely affixed to the wheel?

Speedo cable is tight and speedometer works fine.

prof_stack · **Reply #3 on:** November 24, 2010, 12:50:34 am

Quote from: singhg5 on November 23, 2010, 11:15:37 pm

Speedo cable is tight and speedometer works fine.

Drat, I was hoping for an easy fix.

singhg5 · **Reply #4 on:** November 24, 2010, 01:11:52 am

Another piece of info that I should add is that the top half of brake pad is in full contact with the top piston. But the bottom half of brake pad does not touch the bottom piston. When riding, the pad oscillates like a pendulum and it hits the bottom piston with a 'kTak'.

@Prof: Does you front wheel rotate freely ? Do you need more push to turn front wheel than rear wheel ? Once turning, does it stop quickly as if the brake is always on ?

gashousegorilla · **Reply #5 on:** November 24, 2010, 01:18:36 am

Singh, check and see if you are missing your brake pad Tensioner, should be a metal plate up in the caliper body ,above the pads. Also try some silicone grease on the pad pins, you know, where they slide? You may just have that gap because you have the wheel/ rotor off, and you may have worked the brake lever a bit. and pushed the pistons out? Sounds like your pad is rattling as you ride. If the rattling stops when you apply a little brake, that's most likely it.
Also make sure your pistons are operating correctly, you know, in and out as you apply the brake. Look for any brake fluid around the pistons.

r80rt · **Reply #6 on:** November 24, 2010, 03:28:30 am

one of the pistons may be stuck, I've seen that happen before.

Ducati Scotty · **Reply #7 on:** November 24, 2010, 06:09:32 pm

Quote from: gashousegorilla on November 24, 2010, 01:18:36 am

Singh, check and see if you are missing your brake pad Tensioner, should be a metal plate up in the caliper body ,above the pads.

+1. There's are little prongs on the plate that grab the top of the pad. See if they're all there and not bent over. Checking to see that the pistons are not fozen is a good bet too.

Scott

singhg5 · **Reply #8 on:** November 25, 2010, 06:01:29 pm

Quote from: gashousegorilla on November 24, 2010, 01:18:36 am

Singh, check and see if you are missing your brake pad Tensioner, should be a metal plate up in the caliper body ,above the pads. Also try some silicone grease on the pad pins, you know, where they slide? You may just have that gap because you have the wheel/ rotor off, and you may have worked the brake lever a bit. and pushed the pistons out? Sounds like your pad is rattling as you ride. If the rattling stops when you apply a little brake, that's most likely it.

Also make sure your pistons are operating correctly, you know, in and out as you apply the brake. Look for any brake fluid around the pistons.

@GHG, @r80rt and @Scott:

1. Tensioner (spring plate) was cleaned and fitted in the caliper.
2. Did grease the pins. Pads moved smoothly.
3. When brake was applied, there was no noise - no 'kTak'.
4. There was no fluid leak at the pistons. However, I do not know if both pistons are even or one piston is stuck. It has been cold for the last couple of days and today it was snowing and the bike is outside. I am unable to check the pistons till the weather is better and warms up a bit.

r80rt · **Reply #9 on:** November 25, 2010, 06:10:28 pm

I doubt that you will have a stuck piston, but it's something to check.

singhg5 · **Reply #10 on:** November 25, 2010, 06:19:51 pm

Quote from: r80rt on November 25, 2010, 06:10:28 pm

I doubt that you will have a stuck piston, but it's something to check.

@r80rt:

Didn't you say that you have seen that happen before in your previous post !! What else could cause this ? Any other ideas ?

Quote from: r80rt on November 24, 2010, 03:28:30 am

one of the pistons may be stuck, I've seen that happen before.

r80rt · **Reply #11 on:** November 25, 2010, 06:47:18 pm

I have seen it happen before, not on a RE, it's rare but it can happen. Just trying to offer you a possibility.

Maturin · **Reply #12 on:** November 25, 2010, 09:09:55 pm

Hi Singh!
I´m afraid that could be a stuck brake piston. It should slide smooth and straight back whereas yours looks like it is tipped and therefore has nor full contact with the pad.
Stuck brake pistons happen quite frequently in cabs or other cars that eat kilometers. Reason are grooves in the piston and wear all around the diameter, sometimes combined with loss of brake fluid. They simply tip a little bit and get stuck. I´m surprised that your Bullet´s is causing difficulties with only 10k miles, but sometimes it´s just bad luck. I once lost a Mercedes calliper due to the same problem after 50k kilometers, the replacement made then additional 400k

You can try to make them move again by sheer force, supported by a small amount of grease, but I doubt it´s woth the efford cause you only delay the end and will never know how effective your trial was until it´s stuck again. Maybe the calliper isn´t costly - this said if it´s actually the case the your´s is done. I guess you have to disassemble it.

gashousegorilla · **Reply #13 on:** November 26, 2010, 02:19:42 am

That piston does look like it has some pitting on it? Unless that's just road debris or brake pad particles? The other piston, we can't see, if it's out further,as r80rt and maturin said, that could very well be it. I have seen pistons corrode and pit on bike's that stay outside with less milage then yours Singh. Remember, that Dot 3 or 4 brake fluid is highly corrosive, .There may be a thin sheen of it left over on the surface of the piston, if the seal is weeping a bit, as it goes in and out. Then it's exposed to air and moister, making thing worse.
If that's what it turns out to be, your wellcome to bring the caliper down, and we'll pop the pistons out with my compressor, if you don't have one, and replace the seals and pistons.

Ducati Scotty · **Reply #14 on:** November 26, 2010, 03:08:04 pm

You should be able to press the pistons in to the caliper, usually by hand. Try it next time you have the caliper off. It will take some force and you may want to lay some thing across to press on. Try each one individually.

Scott

r80rt · **Reply #15 on:** November 26, 2010, 03:28:50 pm

I use a small C clamp, works great.

singhg5 · **Reply #16 on:** November 30, 2010, 01:06:46 am

Quote from: gashousegorilla on November 26, 2010, 02:19:42 am

If that's what it turns out to be, your wellcome to bring the caliper down, and we'll pop the pistons out with my compressor, if you don't have one, and replace the seals and pistons.

@GHG:
Thanks for your offer to use the compressor. I am going to see what I can do and if I do not make a headway, I will give you a call.

@Maturin:
Good insights on why and how pistons can get stuck in caliper and your experience with your Mercedes car. Thanks for your input.

@Ducati and @r80rt:
Got a C-clamp and a flat metal plate so that I do not touch the piston edge directly. Not riding daily due to cold / bad weather. Thanks for your advice.

Ducati Scotty · **Reply #17 on:** November 30, 2010, 08:13:49 am

Quote from: singhg5 on November 30, 2010, 01:06:46 am

Not riding daily due to cold / bad weather.

Me either

draggin · **Reply #18 on:** September 03, 2013, 08:36:55 pm

has anyone resolved this? I get the same noise, and the wheel drags at the same time.

barenekd · **Reply #19 on:** September 03, 2013, 09:50:36 pm

You get the noise because the wheel is dragging. Push the pistons back into the calipers a bit. Get some brake cleaner and spray the groove around the pistons and clean the gap thoroughly. That should allow the piston to move and retract as desired. As mentioned clean and lightly grease the pins that the pad assemblies slide on
Bare

Craig McClure · **Reply #20 on:** September 05, 2013, 03:57:08 am

DON'T TAKE FRONT DISC BRAKE PROBLEMS LIGHTLY. Unlike a Drum Brake, A Disc can totally lock up, & put you down-in possibly a face plant. I crashed & totaled my Kawasaki W650 last year, from a LOCKUP. Fortunately no face plant, but I tumbled over & under the bike quite a way. Only damaged my left rotator cuff(shoulder) Now healed. I will never again ignore a SLIGHTLY NOISEY OR GRABBY DISC.

draggin · **Reply #21 on:** September 05, 2013, 05:45:47 pm

I cleaned and lubed mine and they stopped dragging, but I did notice that the front brake disk has a slight wobble to it. I will take it to the dealer for that, but the noise and sticking are definitely gone once I disassembled and lubed the caliper! just a very slight oscillation since the rotor is out of true.

Thanks Singh for posting the great front caliper video!