New Disc Brakes

Ben45

I fitted my rear disc brake to my bike but made the silly mistake of removing the pad spacer between the pads before I was ready to attach them to the rotor. Currently the pads and caliper are't attach to the rotor because the pads aren't wide enough. How can I make them wider?

Thanks for the help!!

MarvintheAndroid

What type ? Some brakes have pad contact adjustment.

If not, and assuming you don't want to go down the LBS route, you will need to let out some fluid to give you space to move the piston(s) back. First remove the pads and put them aside. Then open the bleed nipple a small amount while you move the pistons wider apart using a plastic tyre lever or a large flat screwdriver with insulating tape wrapped round the tip. Close the nipple after each movement. A second pair of hands is useful.

When the jaws are open, clean the caliper and re-fit the pads (being careful not to get any mineral oil on them). Then attach the caliper to the mount.

Pump the brakes a few times to seat the pads. At this point you will need to bleed the system as some air will likely have got in. Best get yourself a bleed kit before you begin.

Park Tools has a useful section covering most makes of brake. The process you need is similar to fitting new pads except the calipers are not on the bike. http://www.parktool.com/repair/byregion ... Field2.y=9

Isopropyl alcohol is worth having handy for cleaning components (and is also brill for fitting handlebar grips too) and can be obtained from your local chemist for a few pounds. Ring first to pre-order.

Marv

supersonic

You may be able to just push the pads/pistons back manually, if its an open system which it likely is. The extra fluid will return to the reservoir.

MarvintheAndroid

Yes, I too have found this is possible if you don't need to gain much clearance, so you may be lucky. Take the pads out first to avoid damaging them.

If you need more help it would help to know what make / model of brake.

Marv.

creeky

I had the same problem when I fitted mine last week, Mine are shimano's with a reservior at the lever, I was able to remove the lid on the reservoir, remove the pads, push the pistons back with a soft lever, refit pads & spacer then pump the lever to set the pistons correctly, then put back together, Job done!