I had what I believed to be a sticky piston on my SLX brakes.

So following various online instructions I removed the wheel, then the pads and slowly worked the pistons out whereby I cleaned and greased them with red rubber grease.

I popped the pads back in but now my lever travels all the way back to the bar and the pistons don’t clamp the rotor with any signficant force.

I’m 99.9% certain I didn’t move the pistons too far out and loose fluid so any ideas what the problem could be?

its probably air from the lever reservoir moved into the hoses, pump the levers repeatedly and zip tie em to the bars overnight, if that doesn’t work then you need to bleed em again..

Would removing the reservoir cap on the lever and gently pumping the lever help to remove any air bubbles?

I tried the tying to the bars trick but that didn’t seem to do much. Wanted to avoid having to do a full bleed an all

it’s going to be air in the system iam afraid your going to have to bleed the system it’s the only way to be sure to get rid of it

Khani +1, don’t need to remove anything, just pump &/or lever tied to the bar overnight. Though if you’ve tried this, they may need bleeding.

So I followed the above and pumped the rear brake until my forearm was bulging and I could feel the lever feel returing. Zip tied overnight again and felt fine on this mornings commute.

I didn’t fancy a bleed until I’ve got a workstand as bike maintenance leaning against a wall is always tricky.

Cheers all 🙂

OK, the point here is that the air’s still there in the resevoir, waiting to strike again… A good bleed leaves none in the res either. So for all it works now it’s worth finishing the job to stop it from happening at some other inconvenient time.

Yep, you’re right Northwind. Brakes have gone back to being a little spongy so a bleed it is then. At least the pistons are nice a free…