Hope Disc question

[harmertrials]

Received a hope trial zone front disc the other day knowing it needed some work.

Coming from a background of pretty much sticking to nothing but magura, vee and the odd avid bb7 I have little to no knowledge on hopes.

Have just given it a rebleed following the hope video guide and there is no air coming out of the pipe anymore...

However, there is some sort of breather hole in the side of the lever cap - Can be seen here:

This is leaking fluid with every brake pump, and when the lever is upside down obviously leaks more.

Also the pistons wont fully return (even though i prised them open throughout bleeding).

Any idea what's going on? Am I just being an idiot and missing something obvious here?

Edited September 3, 2013 by harmertrials

[bing]

My mono trial does the same thing, anyone care to shed some light on it?

[harmertrials]

My mono trial does the same thing, anyone care to shed some light on it?

Do you have to rebleed it often Dan? Surely you can't even lay the bike down?

[AdamR28]

Sounds like the diaphragm is either dead, not seated correctly (common - people overtighten the reservoir bolts, they literally only have to be nipped down, no more), or missing.

Pretty sure it's the 07 one: http://www.tartybikes.co.uk/disc_brake_spares/hope_mini_lever_diaphragm/c110p10151.html (appears to be the same item as in this kit: http://www.tartybikes.co.uk/disc_brake_spares/hope_race_trial_zone_lever_rebuild_kit/c110p11993.html)

[harmertrials]

Sounds like the diaphragm is either deal, not seated correctly (common - people overtighten the reservoir bolts, they literally only have to be nipped down, no more), or missing.

Pretty sure it's the 07 one: http://www.tartybikes.co.uk/disc_brake_spares/hope_mini_lever_diaphragm/c110p10151.html (appears to be the same item as in this kit: http://www.tartybikes.co.uk/disc_brake_spares/hope_race_trial_zone_lever_rebuild_kit/c110p11993.html)

Nice one adam, do you have any of the torx bolts? one of mine is very much rounded which wont be helping.

Also, any idea as to why the pistons wont return fully? Both sides rub on the rotor.

[bing]

Mine is brand new, I got a full lever rebuild kit off the crc website. So over tightening can cause this problem? I'll have a rebleed and let you know how it goes. Mine is an 06 model, the old really solid looking lever. Shame it flexes like hell

Nice one adam, do you have any of the torx bolts? one of mine is very much rounded which wont be helping.

Also, any idea as to why the pistons wont return fully? Both sides rub on the rotor.

Saw a slot in the bolt so it can be removed with a screwdriver

[dezmtber]

I would suggest. Try taking out the master cylinder check the seals are not cut or broke.

If there ok refit then with slicon oil or fork grease.

If the resovoir seal doesn't work.

[bing]

My seals are brand new, only been on a week, and I did it all properly, using a method my mate in a bike shop uses

[harmertrials]

So any clues as to why the slaves wont return?

[AdamR28]

So any clues as to why the slaves wont return?

Be linked to the top bit, or just sticky from lack of maintenance.

Here's the bolts: http://www.tartybikes.co.uk/disc_brake_spares/hope_reservoir_bolt/c110p11213.html - can cut a slot and use screwdriver as said though.

Fit new diaphragm, bleed, spray silicone on pistons, pump brake a little, push pistons back, repeat last 2 steps a few times, then clean up thoroughly and good to go

[UK_SPAWN]

Iv had a lot of these problems and have solved most of them.

The leaking from the top cap is normal after a re-bleed to a certain extent as long as the diaphragm (rubber seal) is seated correctly and is of good condition (not warped, curved bent stretched or gone hard) and you dont overtighten the bolts then after a day or so of an little oil coming out and a "air sound"... it should stop leaking.. this is just because as you fill the reservoir up and "roll on ( very important)" the diaphragm, you allways end up with a little fluid around the diaphragm and reservoir rim and sometimes a few drops in top of diaphragm from spillage etc. Then when the top cap is secured, pulling the lever and pressuring the system causes tyat excess fluid to be ejected through the waste hole. I wouldn reccomend using brakes in the reservoir upside down position as this will allow air to enter into the system again if there is any trapped under the diaphragm as u rollit in.

So. After you do this.... next bit... do a rebleed again and then wait a few days before inverting the bike. (So the excess flud can dissipate)

Ok so the slaves are self adjusting so the wont fully return to he position you push them back to..

A solution is;

Remove calliper.

Install old pads or somthing to hold the piston like a pad would. I use a metal stick thats thin and fits in there.

Push/pull the pistons back as much as you can and then pump the lever as you watch the calliper. Stop pumping before the pads touch so you can prise it open again..(and dont pop the piston out lol)

Repeat this many many times and put some lube (I use gt85) around the rim of the pistons before you press them back in again.. repeat wih bith pistons many many times.

oYou may notice one moves faster than the other and returns better etc. To fix. Install a pad on the working / non lazy side and then a small allen key through the slot that the disk travels through as to stop the good piston moving (try to center everything nicley so that the piston dosent just get restricted fro the front and the back starts to raise...)

Now exercise and lube the lazy piston a few more times and push it back. Remove the jigg you made and push back both pistons as.much as possible (with old pads on).

Test it again. It should be better but maybe not solved. If not then it needs rebuilding and a proper seeing too. However it should be better and should work even if one is moving more freely u just have to set the lazy pads distance to the disk first while you restrics the movment of the free moving pad. So you try to manually get them as close as you can. Then gently work the lever and watch the pads and tweak untill both are touching and releasing properly.

Sorry for bad writing im on the phone. Hope it helps.