brake failed the other day for no apparent reason whilst descending on the quantocks (not fun) bled them the normal way to no avail, no air on system so i'm assuming i have a leak somewhere (bladder in reservoir?)

does anyone have any knowledge of these brakes so to suggest a possible/common reason for failure. hoses all intact and no apparent leaks in caliper/reservoir.

cheers.

oh and this comes just in time for the bonty 24/12 on saturday..joy!

Can't see how if you managed to bleed them properly, you wouldn't be able to see there is a leak or not as as soon as you squeezed the lever, it would piss fluid everywhere 😕

yup thats what im thinking. bled loads before without problem and with the proper kit, it has me puzzled.

What happened when you pulled the lever back after bleeding? Did you push the pistons right back before bleeding: did they move freely? Are they 7s: did you turn the pad contact knob all the way to the “out”
position? tbh that is puzzling. ❓

yeah they are juicy 7's ultimates.. pad contact thingy all the way out.

straight after bleeding they were ok, but rode them for an hour and 10mins into riding they were ****.

bled as per youtube instructions with out drama with proper kit, always rocksolid normally but this time they have a little 'give' to them.

puzzling me too.

Similar thing happened with my old hayes hfx9's. Turned out to be one of the copper washers was damaged at the caliper. Fragile things disc brakes!

im hoping it isnt something stoopid like that as i can't be doing with a full stripdown and rebuild, at this late hour

My heart goes out to you dude. Hydraulics melt my head. I have a brand spanking new set of "pre-bled" 3's. They feel very spongey. Lever nearly touches the bar when pulled. Going to have to give them a full once over now before I ride the bike now.

If there's no external fluid leaks then you've either not fully bled them, and air that was sat in the reservoir is now in the pressurised side of the system(quite common with Avids, even factory bled, probably what Karma is suffering with), or your primary seal on the master cylinder is leaking and bleeding pressurised fluid back into the reservoir.

Ive read loads and loads of topics across many forums about Juicy brakes now. They sound somewhat hit or miss, especially when it comes to bleading. Id say your right about there being a common problem but Im afraid if not somewhat thankfull that I havent experianced it myself so I cant speculate what causes it.

Try pulling the lever and then strapping it back with a toe strap or a tie of some sort. you then leave it like that overnight. the theory of pressure means that the air will float to the top of the resivoir… you can then take the cap off and top the fluid all the way up. you then put the cap back on, when doing this it should be so full that some fluid leaksout… you then have a fully bled syslem.

I have been having an ongoing ball-ache with my Juicy Fives all year.

Evantually I did this, Formula Oro K18's £150

Couldn't be happier,

Alex

yea i have shimano brakes on all my other bikes, they always feel ace, never need bleeding, and only cost £100 for both ends and rotors and bleed kit…

hmmm

gonna try a new bleed tonight to see what happens,

To even it up, I've had 9 Avid Juicys in total (3's and 5's) and not had a problem with any of them at all. I've found bleeding them a doddle and they feel great at all times.

Not saying people don't have problems with them, I just want people to know it's not all bad news.

In terms of fixing your specific problem, I'd try leaving them with the lever depressed (as coatesy says) or else it'll be something requiring a full strip down.

I've had an ongoing issue with a juicy 5 that came on an SC superlight – sometimes the lever pulls all the way back to the bars, other times it feels fine and sharp – no amount of bleeding would fix it and jungle have been working hard to sort it for me. Their mechanic has told me that fisher, the distributor, suggested changing the lever piston seal, which can apparently wear over time, and which they are doing for me. Kudos to Jungle for fixing it (assuming it does), it's an ex-demo one so there was no dealer to handle it.

I have two other pairs of juicys, both a year or two older, which have been no problem at all.

dano = nail on head, i do this everytime i have a problem with mine and it never fails to sort itself