so I changed my brake pads the other day. The pads seem to just clamp onto the disc and not come back. I had a closer look at the caliper and one of the pistons doesn’t seem to move so well, hard to push in and slower to move out when the lever is squeezed. I’m guessing the pistons should move at the same time?

Does anyone have any tips on getting the slow piston moving if that is likely to be the problem, I’m hoping to avoid a trip to the shop

thanks!

Google it there’s better explainations on there.

You either need to sand down the back of the pad if it is painted, release some presure by opening the bleed valve when you push the pistons in or you may be able to achieve this by pumping the brakes very gently and pushing the pistons back.

Or you could lube the piston seals.

thanks both.

re: lubing the piston seals. any particular lube ? shall I just take the pads out and spray something light down the side of the piston?

Make sure you have the bike the right way up for this and not upside down. Use a workstand if you have one. Remove the wheel leave the pads in pull the brake leaver softly and slowly so the pads are almost touching. Remove pads drip some brake fluid on the pistons (make sure it goes all around) and push the pistons back in genitally with a small ring spanner, wipe off excess brake fluid. Replace pads and wheel and pump the brake for a bit. It should be a lot better.

EDIT: Dont spray any lube at all on the pistons by lubing he means use brake fluid!

thanks for the tips. I will give that a try

push the pistons back in genitally with a small ring spanner

Define “Genitally” 😯 😯 😯

Dont spray any lube at all on the pistons by lubing he means use brake fluid!

Silicone lube is better than brake fluid. The spray stuff from 3-in-1 is excellent for regular maintenance.

Try the method described at the beginning of this guide.

Sorry about the genitals bloody spell check.

If your use any lube it will contaminate the brake fluid.

I will be sure to be genital with it as you suggest.

sounds like I need some dot 5.1 then. If this doesn’t work I guess from the guide above that it could be a seal failure and that will need a new seal and a re-build. Is this best left to a bike shop?

ah- I see screwfix have the silicon spray, I will get a can of that tomorrow