Magura brake adjustment

I wish to shorten the brake hose on a Magura HS33 hydraulic brake.
Straight out of the box the hose from the level to the master cyclinder is too long. Once I have fixed the bits to the unicycle I want to adjust the length of this hose.

If I disconnect the hose will I lose fluid? Do I have to do anything to stop fluid leaking whilst I am shortening the pipe? Any tips on doing this job?

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You’re definitely going to have to “bleed” your brake after you finish adjusting the length of tubing. See:

for starters on that. Also, most likely, you’re going to have to use a new barbed fitting to put into the shortened tubing as it is unlikely you’ll be able to reuse the existing fitting (you can try but it’s a devil to get it out of the old tubing and then there is always the possibility of leaks) so do yourself a favor and get one of the “bleed kits” magura sells that comes with all the little replacement bits.

I can tell you it’s a lot of trouble messing with all that tubing, if you can get by with a longer tube by just wrapping it around your seat post I’d do that, the real issue is having enough length on the cross-over tube (the tube that connects both brake cylinders).

Also I will say I had a lot of trouble “bleeding” my adjusted brakes (I too bought some more tubing to give a better fit of the brake lines for my KH24), I don’t think I had all the right little bits and pieces to do it right. My solution, which I copied from others on this forum, was to use good old water as brake fluid and just did the whole bleeding process in a large bucket full of water. Done and done it was a snap! WARNING if you ride in sub-freezing weather be advised your brake line will freeze! I experienced this last weekend when I noticed my brake pads were rubbing on the rim sometimes when I was climbing. I went to pull the brake lever and it wouldn’t move! FROZEN! I kind of laughed as I remembered I’d used water in the brake line. I’ve had no brake trouble for almost 8 months now, the water has worked perfectly. No problem, it rarely gets below freezing around here anyways!! I imagine one could use a different solution other than pure water to avoid the freeze issue, perhaps some anti-freeze? But don’t take my word on that all I know is water works fairly well.

If the system comes pre charged (i.e fluid already in the system) then yes you will lose fluid by disconnecting a line.

I base this statement on automobile brake systems as I have not dealt with the Magura stuff. Automobile hydraulic components are all shipped dry and require you to install the fluid yourself.

Anti-freeze will work in hydraulic brake systems (at least any thing that would normally use up to DOT 3 brake fluid) It is the only recommended fluid to use in an emergency as it will not rust any of the internal brake components

Magura brakes run on mineral oil, not on car type brake fluid. If you need an emergency brake fluid, it says to use cooking oil.

Although you can get 5 litre containers of a mineral oil that is supposedly equivalent to magura fluid at most car places - it is called something odd, I think Citroen suspension fluid or something. Thinking about it I don’t know if you have Citroens in the USA though.

If you are very careful, it is supposed to be possible to shorten maguras without losing the oil or needing to bleed them.

In terms of tips, my top tip is to download the manual from - it is easy to do things wrong if you don’t have the instructions.


If you just want to shorten the hose from the lever to the first slave cylinder then all you need is a new olive for the connection (you probably won’t be able to reuse the olive because they squash when to do them up and grip the hose). There are no barbed connectors on that hose at the caliper end (the barbed connectors are on the hose between the two slave cylinders).

If you’re careful and use a sharp knife then you can undo, cut and refit the hose at the slave cylinder end without losing any fluid, and won’t need to bleed the brake. The fluid will run out of the bit of hose you cut off, but (as long as you handle it carefully and don’t wave the hose about) it’ll stay in the closed hose still attached to the lever. I’ve done that twice with Magura brakes (HS66 on my tandem and HS33 on my muni) and not had to bleed either (and no they’re not spongy and didn’t get air in them). The hole in the middle of the magura hose is much smaller than on normal car-type hydraulic brake pipes, so the fluid tends to stay in quite easily as long as one end of the hose is still sealed. In fact, I think it actually suggests in the Magura manual that you probably won’t need to bleed the system after shortening the hose.

The hose between the two slave cylinders is more of a pain though - if you need to alter that one you’ll have to mess about with the barbed connectors (you can sometimes salvage the old ones by slicing the side of the hose open) and will almost certainly need to bleed it afterwards.


Shorthening Brake cable

I don’t have any brake bleeding exp. (I have heard it’s horrible) but to shorten the cable you will need to cut it. If it is the steel braided cable that will be hard. There are special cutters for it because it’s easy to mess up the braid of the cable and unravel the steel if you cut it wrong.

I say wrap it around your tube, why go to such extra hassle just to have a shorter. tighter cable, it’s better to have a loose one for when it gets banged around.

Ignore this if you don’t have the steel brake lines


Wrap around the tube

I think it looks good anyways (My old rail seatpost in photo)

I strongly recomend using water, its way easier, cleaner and cheaper to bleed and it makes for a much much softer leaver. You just have to be careful when it gets cold. maybe use anti-freeze.

Thanks for the brake info Joe. I’m in Canada and have to suggest that I haven’t seen a Citroen around for years. They were never marketed here that I’m aware of. As the Citroen has or had an adjustable load leveling / comfort suspension system this was likely the fluid that they used in their suspension lines.

Thanks for this feedback RN. Yes I only want to shorten between the master and first slave cyclinder. UDC sent a spare olive in the box so that was convenient. Yeah I read the manual about not needing to bleed the brake after shortening but thought I would post this thread to see what others had done. At present the cable is wrapped around the seat post and T7 but after reading your post I feel more confident at shortening it.:slight_smile:

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The Magura web site has technical and shop manuals online (the manuals are in PDF format). The manuals explain how to cut a brake hose, replace the olive, bleed the brake, etc.

The Magura web site is done with frames so it is difficult to get a direct link.
Here’s the steps to get to the manuals:
Go to
Select the Magura bicycle components
Select language
Go to the “Service” menu at the top of the page
Select “Download” (Those are the available document downloads including the shop manuals)
Select the model year, product, and model
You’ll get a list of available downloads for that product

The Magura Cult is unfortunately no longer online. They had a great FAQ on how to bleed rim brakes. Bummer.

The Magura Cult had a tip to use Finish Line Shock Oil (5wt) as replacement oil for the rim brakes. Many bike shops will have it in stock. It is apparently the same oil that Magura USA uses.

Sorry I can’t help much on the technical side, as my bleeding skills suck, lol. But I think you may have ordered the longer of the TWO sizes that UDC has in the maggie setup. One is the standard, shorter one (18" line) for most MUni setups, and the other is longer for 36ers.(36" line) I made sure to order the shorter one for my MUni and the length was just right, although the crossover was a tad short since I use extenders with a wider rim.

Yeah I’ve found the cross over on mine is too short. I cant get the breaks to sit in the right place pecause the line pulls it out of place again. I need to true my rim anyway though.

I’ve shortened the plastic Magura lines a few times now and have never bled the brakes afterwards or felt like they needed bleeding. I think if you’re prepared and do it carefully as per the manual it seems to work no problem.

Bleeding is a straight forward process though, even if you’ve never bled any similar system. Along with having sufficient mineral blood, having an extra pair of hands to help hold stuff is useful. The only times I’ve bled Maguras is when I’ve swapped to new braided lines and needed to charge the system.

Bit like trying something new on the uni, I think the hardest part about the brake stuff is deciding to give it a go.

Havn’t read the whole thread but here is my experience:

If you do it well you won’t have to bleed it. I did this myself, I have a booster so I can really determine if there is “spongyness” or not. In my setup there is no flex and no “spongyness”.

What I did was to be very careful with sudden movements and fill the brake with fluid to that the pipe is submerged in oil when reconnecting it. Also make sure there pipe a little bulge of oil at the end, everything to make sure no air can get in.

Yeah good comment. I think I will go for it and if I make a mistake at least I can learn from that. Thanks

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Darn! I think your right! I am buying from the UK site of UDC and on that there doesn’t seem to be length options. I don’t think the UDC UK web site is as comprehensive as the USA site anyway Also my cross-over line wasn’t quite long enough to go over the top of the frame and I had to route it between the frame and wheel to make it fit.

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