Brake pads rubbing against discs

[GoBig]

For some reason I cannot get my discs to stop from touching the pads (without braking, of course ). I have an Anthem with Juicy Fives.

 

This is driving me INSANE!

 

If I turn my bike over and fiddle around with the wheels and the pads I get it to be better, but then after braking the first time it's the same story. Also, I tried to replace the brake pads today and had to change back to the old ones since with the new pads the wheels can hardly turn through the pads

 

So what am I missing here?

[mountain_lion]

How did you try to adjust the brake pad?

 

The following normally works for me:

1. Squeeze and release the lever a few times.

2. Loosen the caliper positioning bolts

3. Compress the lever completely.

4. Tighten the caliper positioning bolts a little a time alternating between the 2 bolts (just enough to so that caliper does not move).

5. Release lever and rotate the wheel and check for pad drag

6. Repeat 2 to 5 until happy.

7. Alternatively torque (8-10 Nm) the bolts a little at a time.

 

 

Did you push the pistons completely back before installing the new pad?

 

Use a large flat screwdriver and insert between the old pads and rock back and forth until the pistons are all the way back.

Pistons do some times get stuck (especially if mud and dirt gets in there) and then need a bit more "persuasion" to get them back in.

 

 

[jrussell]

Same problem with the same bike, i loosened the screw on the inside of the brake lever, its a tiny allenkey screw, just loosen it a bit and it will pull the piston out a bit stoping the caliper from touching the disc all the time

[DownhillingKing]

Yes but you have the other avids

[jrussell]

Still got the screw behind the lever

[Wernervdmerwe]

The pistons auto-adjusts to compensate for pad wear, so when you replace the pads, you have to gently push the pistons back. I press against the pads with a screwdriver, not on the actual piston itself.

 

 

 

Sometimes, if you can't get the pistons back by gentle pressure, you have to loosen the reservoir screws just a little and then press them. Please remember to position the bike / lever so the reservoir is level with the ground, else the oil will just pour out.

 

 

 

Once pistons are re-seated, you can tighten those screws again.

 

 

 

Once either / both the above is done, take the caliper off and fold a business card over the rotor. Then replace the caliper over the business card (you have now basically increased the thickness of the rotor).

 

 

 

You then compress the lever a couple of times (lightly) to compensate for the adjustment of the pads.

 

You can now tighten the caliper while holding the lever in, no need to press the lever as if trying to bend it though.

 

 

 

Faster the bolts on the caliper, roll the wheel and the business card will pop out. At this stage you should have rub-free disks!

[Daxiet]

I have always had that problem with my Juicy 3.5s. I had to come to accept some amount of rubbing if you fiddle with them you can get them to behave for a couple braking shots, but they will revert back to their bad behaved selves.

 

It could simply be a build up of fin dirt between the pistons and the walls of the caliper which does not allow the piston to push back slightly after braking. I tried cleaning mine with some success.

 

As mentioned by others, push the pistons back when installing new pads.

 

On my new bike I have XT brakes and they are awesome, but they are new so they become bad behaved, but for now they are a pleasure.

 

[GoBig]

Guys

 

Thanks for all the advice.

 

ML, have tried your method with some success and they are not rubbing any more (for now...).

 

Since I'll be in JHB for the next two weeks I decided to not try and replace the pads before the Transbaviaans in case I $&%# something up and don't have time to fix it before then. But I will try your method then Werner - thanks!

 

Btw - the pistons did seem to need some, uhm, pursuasion to move back and I still can't them to be flush with the inside of the calipers - are they supposed to be? Didn't want to force them too much in case I break something.

[Daxiet]

To my recollection I would say the pistons could be pushed back close to if not totally flush.

 

I would push them back, then pump the brakes a couple times to ensure they come out quite far then sprayed with brake cleaner and then pushed them back in again. Repeated these steps until the pistons behaved in a more consistent fashion. Perhaps the proper way to clean them would be to get the full service kit, strip them down and re-assemble them.