Uneven pad wear on XT disk brakes

Hi All,

I replaced the disk pads a couple of months ago so they've had about 400-450km of use. I noticed last night the front pads are not doing what they should, the pad on the piston side is totally worn and the other side looks like new. The rear pads are fine and are fitted the same way as the front, has anyone had or seen this problem before?

Cheers
Steve

Steve,

Are both pistons moving ok? Could be that only 1 is working as it should be?

Is your rotor centered ok? If not, loosen the bolts that hold the calliper on, pull the brake, then with the brake still on, tighten the 2 bolts.

That’s the extent of my suggestions I’m afraid.

As Jase said check the pistons. Sounds like one is sticking after you've applied the pressure and holding the pad against the rotor - hence the wear.

I run Hopes, when I changed my pads I got a lot of squeak and found that the piston had got covered in cr@p as it came out to take up the slack where the pad had worn down. All I did was push it back in which I guess pushed the cr@p into the seal. As standard practise now when I change pads I carefully pump the brake lever to get the piston quite far out then clean it up and spray it with WD40/GT85 etc then work it in/out a few times.

Hope that helps.

Steve, when you look at the caliper there should be a groove in the centre. This is what you rotor should be aligned too. A lot of people make the mistake of lining the rotor up in the middle of the two pads assuming the caliper is in the central position.

If the pistons are not moving in at the same time, I.E one of the pads is touching the rotor first, there is an easy solution.

Identify the pad that touches last, then on the other side, place a screwdriver between the piston and the back of the pad. The squeeze the lever until it goes hard then keep it squeezed for a few seconds. What this does is moves more fluid round the to the oposite piston. Then squeeze the lever without the screwdriver and you should see the pad should now be touching earlier. Keep doing this until both tocuh at the same time.

Ta da !!

Thanks for the advice, it looks like one of the pistons is sticking. I would normally have a go at fixing this myself but with the rough ride this weekend I decided to drop the bike off at Pink's. They've done a few repairs/upgrades over the past couple of months with good results.
Steve