Magura Hs33

[TrialZonn]

Hello.

I'm not disatisfied from my brake performance but I wonder if this is right:

I'm currently running a Magura HS33 setup on my bike and have noticed that:

When I push the lever, only one of the two brake pads are moving towards the rim enough to say that it ''hits'' it's like the other one stays still or move a little compared to the other.

I have setup my brakes a few times and I also noticed that after I brake the one pad stays closer to the rim and the other move back to where it was before braking.

So...is this a problem?Is this what you call ''lazy piston''?

I have bled my brake last week so I don't think that rebleeding it will work.

Setup it again is not going to help either as I achieved a very good setup the last time:both brake pads hit (in that case the one brake pad hit the other just get in contact with the rim because the rim is forced against it) the rim in a great angle.

Please tell me if that's common or it's a problem and what should I do to enchance my brake's performance.

Thanks for your time.

[rab shropshire]

this is how hs33 brakes work when one pad hits the rim the oil is forced to the other side via the crossover which then moves the other pad. the only way to get both pads moving at the same time is to use a hose splitter hope this helps

[r2wtrials]

That shouldn't be the case... the pressure is equal in the system so they should both move at the same time. Although having said that i am now running a monty splitter!!

My previuous set-up had a lazy, notchy piston. I took the pistons off and using a pair of pliers i pulled the piston out and then released. They should snap back into place but one side was very notchy and sometimes wouldn't return at all. Try that to see if you have the same problem... best way to cure it is use a new piston assembly.

Water bleeds don't help as water and alloy don't mix well when moving parts are involved... water being more abrasive than oil. I have seen what a water bleed has done to pistons and lever assemblies and because of my motorcycle background you wouldn't catch me using a water bleed!! But each to their own...

[Echo-Scott]

One pad will stay out aswel if you have done your Tpa up aswel by the way. So incase your trying to find a big problem. Make sure your Tpa is wound right down first.

[James Quigley]

this is how hs33 brakes work when one pad hits the rim the oil is forced to the other side via the crossover which then moves the other pad. the only way to get both pads moving at the same time is to use a hose splitter hope this helps

Wrong!

They should both move at the same time. Just hold the pad that moves in your hands so that it cant move, then squirt some wd40/gt85 on the 'lazy' side and then pump the lever a bit. This should lubricate the lazy cylinder and it should all work allreet again.

[pablotrial]

maybe this can solve your problem

you should have search on the wiki

http://www.trials-forum.co.uk/wiki/Fixing_...ra_lazy_pistons

good luck

pablo

[TrialZonn]

Thanks for the replies guys you help me a lot.

I use oil in my brake (Magura Royal Blood) so I don't think that water is an issue.

I tried lubricating the lazy piston but it didn't actualy worked.So maybe there is a problem inside the cylinder...

Something else that I noticed is that the pad tends not to move only when I have that TPA tightened (I mean screwed so the brake pads are close to the rims)

If I loosen it then after the braking the brake pads move back to their positions normaly (but I haven't much brake power and I must push the lever to much)

Edited July 16, 2009 by TrialZonn

[forteh]

Probably a tiny bubble of trapped air in the lazy piston, when you bleeding the brake try tapping the slaves with a spanner to try to dislodge any bubbles, laying the bike over so the lazy piston is upmost will help draw any air towards the hose/bleed screw. Presuming youre syringe bleeding after you have taken the drain pipe off the lever and closed it up try pushing a bit more oil through the slaves before removing the syringe, this may help to force some trapped air out.

edit: you should set your maguras up with minimal TPA, reseat the circle washers further out on the slaves if necessary. For some reason loads of TPA seems to only move one piston, I have no idea why this is as its only pushing the column of oil further down from the master cylinder.

Edited July 16, 2009 by forteh

[TrialZonn]

Probably a tiny bubble of trapped air in the lazy piston, when you bleeding the brake try tapping the slaves with a spanner to try to dislodge any bubbles, laying the bike over so the lazy piston is upmost will help draw any air towards the hose/bleed screw. Presuming youre syringe bleeding after you have taken the drain pipe off the lever and closed it up try pushing a bit more oil through the slaves before removing the syringe, this may help to force some trapped air out.

edit: you should set your maguras up with minimal TPA, reseat the circle washers further out on the slaves if necessary. For some reason loads of TPA seems to only move one piston, I have no idea why this is as its only pushing the column of oil further down from the master cylinder.

Thanks.

I will try re-bleeding it.(and yes I'm syringe bleeding it)

By the way, I have Tensile offset mounts, so I can setup my brakes either too close or too far from the rim.(so I must use TPA to adjust them)

Thanks for your help.

Edited July 16, 2009 by TrialZonn