Sticky Hs33 Lever Piston

[Muel]

The piston in my Maggy lever is sticking whenever I take the fluid out, what can i do to stop it? It's almost as if the piston has expanded?

I bought a brake off here and returned it because of this, I thought it was a one time thing but now it's happened to this one aswell.

What can I do? A fluid with more lubricating-ness? I could get my Dad to machine a stainless steel piston? It would be a very long job though, he could only fit it in when he had time and I want to ride!

It returns fine when it's bled, but it means that even when it's bled with water it's fairly heavy at the lever.

I could just turn a tiny amount off the piston? That way the seal would be the same diametre still, but the plastic part would be slightly smaller?

Any ideas welcome. I'm not going to buy a new one, as it is new! I built the brake from brand new parts in February. (lever, slaves, hose etc.)

[Ben John-Hynes]

The exact same thing happens to all of my 04 levers.

Not sure why it happens but it's only when there's no fluid in there so it's fine when it's bled. I'd say it was just because there's nothing lubricating it.

[matt rushton]

What I used to do is take them out spray with WD40 then stick it back in, and they worked. Maybe even strech spring abit?

[Muel]

Cheers Matt I'll give that a bosh. I'm also planning on mixing up a new fluid some time this week, so I'll make an emulsion with some oil in it aswell, that should sort it!

[Matthew62]

I had the same problem. I gave mine a really thorough clean, i mean a real serious clean with various lubes and it is better than ever. Just give it some time.

[Al_Fel]

Is it an 05 Maggie? I've found that some of the earlier models of the new shape magura's seem to have over sized pistons in the lever. I think they might have been made slightly too big by accident. I found that if I used the piston out of an older magura it slid in a lot easier.

If you haven't got a spare piston you could try sanding the plastic part of the piston down. You need to take a fair bit off it so it will slide in and out freely without the seal on.

Hope that helps.

I think this might be your problem.

[matt_urban]

dremel with soft polish bit and metal polish on it run it around inside for about 5 mins then put some silicon lube on the bore and seal valaaaaaaaa

[Muel]

Cheers, Thats a great help. I'll give it too my Dad and see if he can turn it or make me a new piston, seems like it's a common thing! The only problem I can see it mounting it in the lathe, as there is nothing to get hold of really.

It's not an old one though, I got it from Trials-UK, it's a white one but it's one of the ones that came after the Eisbar ones.

Anyway, I'll solve it somehow. Thanks.

I do remember when I got it that it was really free and easy though? Maybe it reacted with the water/anit-freeze and swelled?

[Dave Anscombe]

I my self have had to sort out peoples brakes like this.........bleed it with fairly liquid water......opporate the brake lots.......then with a syringe full of air blow out all the shit

bleed with clean water

comes back to life

Dave x

[Muel]

Cheers Dave. I'll be using an emulsion of water and oil when I next bleed it, so I'll try that and see if it frees it off.

[Muel]

I solved it, I took the dust seal out and it doesn't stick now. Looks like the dust seal went hard when it came into contact with water! It's solid.

My f**king emulsion fluid won't emulsify though, the oil keeps floating on top. But seeing as the lever piston now isn't sticking, I'm just going to use water and Pro-Cool.