MTB Brake pad fitting problems

ollie_lucas1985

Hello all..

I tried today to fit some new pads to the ole bike = fail..

I got everthing out and cleaned up the caliper, looked inside and noted the pistons, I then began to push the pistons back into the body - No joy there!

So I go upto the fluid resivior and open the cap just incase It needed somewhere to go, didnt have this problem on the car tho!

I was following my "parktool big blue book" thing and i didnt see a section saying if you cant get the pistons in ..

I did notice on the side that was out the furthest that the pad was 1-2mm less than the other side.. odd!

I can push the pistons into the body but soon as I take the pressure off they come straight back out.. am i missing something?

To sum it up - I cant seem to get the pistons in far enough!!

Anyways, help appreciated!!

They are Shimano M486 hydraulic disc brakes.

nicklouse

so what is the actual problem?

the rotor wont fit or......

ollie_lucas1985

I cant get the pistons in far enough.,.

When I put the pad in there pretty much clamped together completly..

ollie_lucas1985

Any suggestions guys?

02gf74

one way that will do it is to bleed the brake fluid out of the brakes - open up the bleed nipple and push the pistons in.

I had similar on Magura caliper - but I did manage to push the pistons in but brake did not feel right so I bled them and all is well.