Hydraulic brakes binding

[3narf]

Hello,

I just fitted a set of second hand Avid Juicy 3s to my son's new bike and they're binding. I was going to buy brand new Clarks ones but I've had the Avids before and still have a bleed kit.

They work fine but they're binding; I suspect one piston on each caliper is seized and they're just working by displacing the disc sideways.

I was wondering how to best free them off, maybe I'll soak each caliper in penetrating oil. Or will that destroy the seals?

I know the operating medium is always the best thing to lubricate components, so maybe I'll just try & get the piston to move, then soak the whole thing in Dot4.

 

[keithmac]

Push pistons completey out of you can, remove seals (put back in same way up!) Check for corrosion behind the seals and clean if necessary.

If you soak them in oil you may ruin the seals..

 

[Yellow Saddle]

As Keith says. However, if you don't want to push the pistons out completely, just remove the calipers from the bike (hose still attached), remove the pads and put a cone spanner in the slot where the disc slots in. Let the piston rest n the middle part, grip the two ends with your two hands and thumbs on the caliper. Pretend you are breaking a long biscuit.

Push the pad in. the opposite one should now push out. Let it move out past the wear and dirt ring. Once that is exposed, used meths or soapy water and a cotton bud to clean right round the piston. "Paint" a little brake fluid on it before pushing it in with the method described above. Now clean the other side. Replace everything.

Do not use oil or any lubricant/cleaner containing chlorine. Spray lubricants such as silicone which are labelled as Chlorine-Free are suitable. This particular rubber doesn't like Chlorine.

Unfortunately Juicy brakes are the worst of the worst for prolems as you describe. Their phenolic resin pistons practically turn into sandpaper after a bit of use and they never move freely or evenly.

 

[lpretro1]

Have to agree with above comment - the Avids are always sticking w we have seen hundreds of them in our workshop - they are worse if they are left unused for any length of time too. You can fit new seals & pistons but the bits are not very cheap I'm afraid and it doesn't guarantee to fix the problem Juicys and Elixirs all seem to suffer the same problem. We have often tried to clean them up as advised above but a wee while later they often come back with same problem