Front brake caliper pistons won't retract

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Man_Named_Dave
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Front brake caliper pistons won't retract

Post by Man_Named_Dave » Wed Mar 02, 2011 2:17 pm

I just tried to re-fit my (NC 30) front brake pads. The left-hand ones went on ok, but on the right-hand caliper the pistons are pushed right up against the brake pad. The Haynes manual says to use your hands or some wood to push them back in, but they're not budging at all. Do I need to open up the whole blasted caliper or drain off some fluid?
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Re: Front brake caliper pistons won't retract

Post by mattUKNC » Wed Mar 02, 2011 2:22 pm

Hmm, is that with the brake res cap off?!
I have a caliper splitter tool (to hold the pistons apart), but you'd still need to open it up enough to get the tool in. (As it were)
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Re: Front brake caliper pistons won't retract

Post by Man_Named_Dave » Wed Mar 02, 2011 2:25 pm

mattUKNC wrote:Hmm, is that with the brake res cap off?!I have a caliper splitter tool (to hold the pistons apart), but you'd still need to open it up enough to get the tool in. (As it were)
I haven't touched it.

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Re: Front brake caliper pistons won't retract

Post by hardnutdvd » Wed Mar 02, 2011 2:33 pm

take the res lid off, just make sure when you push the piston back the level doesnt spill over the top...
if your replacing the pads, use one of the old pads and use a lever against the pad to push the piston back in.. it makes no difference if your digging and wrecking the old pad.. i used a large spanner as a lever..
if you need to drain off some fluid, use a syringe and take from the res... :peace:

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Re: Front brake caliper pistons won't retract

Post by Man_Named_Dave » Wed Mar 02, 2011 3:04 pm

I gave that a try, Hardnut, but no joy. The pistons squeeze a little but don't retract.

As for the res, the level is actually right on the bottom of the lower line.

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Re: Front brake caliper pistons won't retract

Post by mattUKNC » Wed Mar 02, 2011 3:11 pm

Man_Named_Dave wrote:I gave that a try, Hardnut, but no joy. The pistons squeeze a little but don't retract.

As for the res, the level is actually right on the bottom of the lower line.
That will rise as the pistons go back to where they should be.
Have you got a long screwdriver to get in there? :?
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Re: Front brake caliper pistons won't retract

Post by Man_Named_Dave » Wed Mar 02, 2011 3:17 pm

mattUKNC wrote:That will rise as the pistons go back to where they should be.
Have you got a long screwdriver to get in there? :?
There isn't even half a mm between the pad and pistons. I can't get a flathead in there at all.

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Re: Front brake caliper pistons won't retract

Post by mattUKNC » Wed Mar 02, 2011 3:44 pm

Man_Named_Dave wrote:
mattUKNC wrote:That will rise as the pistons go back to where they should be.
Have you got a long screwdriver to get in there? :?
There isn't even half a mm between the pad and pistons. I can't get a flathead in there at all.
Hmm, you're quite close to me aren't you? PM your address and I'll see if I can get over there. :up:
(I'll bring the 'big' hammer.)
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Re: Front brake caliper pistons won't retract

Post by hardnutdvd » Wed Mar 02, 2011 3:46 pm

can you undo the pad retaining pin and little retainer plug, remove the pads and then use one old pad against the pistons with a lever to push it back in?
with the pin removed you might be able to rpise one pad out?

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Re: Front brake caliper pistons won't retract

Post by ludacris » Wed Mar 02, 2011 3:52 pm

that's some crazy pressure you have there. out of curiosity, u didn't by any chance squeeze the brake lever when you put the 1st side back on? stupid question i know but it can happen

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