Superstar components - ??

antfly

All the patience in the world doesn`t help if the pistons won`t go back,I tell you.Nobody has come up with an explanation or resolution yet so it looks like I`ll have the same trouble every time I change the pads.

Northwind

That's weird... I've never used those brakes but presumably there's nothing mechanical stopping the pistons from backing up... If the reservoir was filled with part-worn pads you might find that there's just not enough room in the res to accomodate the fluid pushed back when you back the pads off, that'd do it. But not very likely.

Hmm. Most hydraulic brakes have a diaphragm in the res... It works by expanding to fill up the space that the fluid leaves behind as the pads wear and the pistons, basically becomes a balloon- the air's kept away from the fluid. But, with some brake systems, when you try and push the piston back, the balloon doesn't vent to atmosphere fast enough, so the piston can't retract (when it expands, it does so incredibly slowly, so even though it's practically airtight that's enough). This is more common with systems designed to work either way up, from what I've seen, as they have to be more tightly sealed. It could be causing this... Have you tried pushing the pistons back with the reservoir cap off?

antfly

Thanks,that sounds plausible.No I`ve never tried it with the cap off, I will try it next time but I need to get a T10 torx key to get the cap off first.

JK in the UK

I said I'd update if I remembered who else I got 'dodgy' pads from - mtb-direct. However their aftersales was fantastic, I sent the pad back to them so they could assess them and a refund was issued no quibbles. No complaints there whatsoever - I don't want to unnecessarily damage a company's reputation. They claim (like Superstar Components) that it was a problem with early batches and should be resolved now....hmm.....

I do hate to say this, but assuming the pistons retact, replacing Juicy pads couldn't be much easier! Obviously you seem to have other issues! Definately try it with the reservoir cap off seeing as you don't seem to have any luck with the alternatives, but I would say make sure when you put the cap and diaphram back on, make sure the reservoir's full of fluid and no air is in there otherwise you could be setting yourself up for further problems down the line....

Also be aware when you push the pistons back have a rag around the reservoir - the fluid kind of 'pops' out and splashes all over your bike. I used to have some real basic closed system cheap 'n' nasty Grimeca brakes on an old HT and learnt that to my peril. I was a lot younger and didn't realise how corrosive the stuff was to paint and didn't notice it on my pads !

I must say Juicy's are not without their faults - I've got 5's on my HT and I love them - great reliable stoppers. The 7's on my FS have been the bane of my life. They've been bled 3 times by the shop I bought the bike from and sent away and resealed. Still they seem to randomly lose pressure and then come back. They don't have the same solid feel at bite point as the 5's are just crap. I much prefer the 5's as all the contact adjust rubbish is a complete con. I even bought a bleed kit myself in frustration that maybe the shop are useless too - nope. I've bled those brakes more times than I care to mention. They're better but nothing like my 5's............