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Help me save my brakes

691 Views 2 Replies 2 Participants Last post by  jb0000
Hey all, my set of Formula Cura 2's has developed a weird issue.

The brakes are 3 years old and now I'm finding the lever stroke to be about twice as long as on new ones, rendering them next to useless.
Bite point is firm which points me away from the master cylinder being the source of the problem.
It seems the pistons are retracting much farther back than normal.

I have tried cleaning and freeing up the pistons, which proved difficult as they barely extend even after 50 lever presses. Likewise, attempting to push them back in I'm met with a lot of friction from the seals. I have also tried a caliper rebuild with all new seals, but the issue remains. It is even difficult to push the old pistons into new seals (lubed, of course).

The only fluids that were in contact with the seals are Formula mineral fluid and isopropyl alcohol.

Can it be a case of worn out pistons exerting too much friction force? Being such a gradual change I suspect this might be the case, however the pistons don't feel too bad.
Any other possible explanations?
1 - 3 of 3 Posts
Maybe wear at the level mechanism?
There's definitely a bit of play at the bushings but I can't see that causing more than a couple mm of stroke difference.

Now I'm sure the pad clearance is the main symptom, because when I extended the pistons to allow normal pad clearance the lever stroke went back to normal. For half a ride...
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