- Tech help needed – brake pistons won't fully retract
make sure there is no muck or build up on the pistons. Maybe careful clean the pretruding part and add a little brake fluid if you have any and push back in. Sometimes if the push/pressure isn’t perfectly square then the pistons do not go back in too.
post above ^^ is probably most relevant thoughPosted 4 years agoalanlMember
I had this trouble on some Avid Elixirs.Posted 4 years ago
Tried all sorts to get the new pads to fit to no avail. It turns out to be a common fault, where the original pads are a mm or so thinner than new ones, and the fluid in the reservoir was put in to suit the thinner pads, so, the pistons could not be pushed all the way back in, not matter what I did to them.
Draining the excess fluid off cured it – I undid the hose to caliper bolt slightly, then pushed the pistons into the body, which forced some of the fluid out of the hose fitting.
No problems then. I hadnt realised the brake lever had such little movement until I did that, I’ve had Hopes before, and just thought the lack of movement was the way Avids were, but suddenly there was some feel again to my brakes.
Could use the ring spanner to push one piston back at a time, no chance of fitting two spanners in there.
I’ve now managed to loose the tiny clip which stops the pin holding the pads in coming out ( although it is threaded ).
The brake fluid has never been touched since I’ve had the bike and pads fit last time so I’m cautious about releasing fluid ( especially as I don’t class myself as a competent bike mechanic ! ).Posted 4 years ago
Please could anyone offer advice on how to get the brake pistons to go fully back in to fit new pads.
I’ve fit numerous sets of pads without problems but this time the pistons won’t retract and remain there. I can’t get both sides to fully retract at the same time. I can push each side back using an old pad but they don’t stop there once released.
Once the new pads are inserted there is no chance of the rotor fitting in.
I’ve tried with used pads from the front but I can’t even get the rotor in with those.
As I’m one of the few on here with just the one bike it looks like there’ll be no riding tomorrow … or next week now 🙁Posted 4 years ago
Still no success, rounded the hex of the threaded pin now ……
I don’t seem to have anything which undoes the bleed screw and I have tried opening the lever adjustment as much as I can without success.
Patience lost I’m afraid, the bike will be going to the bike shop to be fixed by someone competent.
Thanks for the prompt help anyway !
It’s wine o’clock now then as I’m not riding tomorrow !Posted 4 years ago
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