bleeding the Maguras

I only yesterday, finally got around to attempting to bleed my lines on my Magura HS33’s.

I have the bleed kit, that came with some steel braided lines. An LBS did the conversion to steel from plastic lines back in early October. Damn crossover line popped out at CMW on the final day just from a fall as it hit my ankle. I think the crossover line was never fully threaded into the nut.

Anyway, I decided to go for it myself. The first time, I had no pressure in the line. I blew out the line with a syringe and started over again. This time, making the bleed valve as horizontal as it can be… This time it came out better, and felt solid on the driveway. But out on the trail, today, it didn’t feel that strong.

Does anyone have any tips on how to get that bleed valve/brake lever mount horizontal? I became a contortionist as I held the bottle, the brake lever, and pressed the syringe. The uni was leaning up against the wall with the wheel chocked on both sides.

Also, any tips on how to get the screw back in on the slave and the bleed valve nut in there without getting air in the system? I closed the bleed valve first in the handle, as instructed by the manual. I suppose that creates a vacuum in the line, so the fluid won’t leak in the slave as you replace the bolt, though not sure.

Cheers.

I asume you are using oil. I use water (along with alot of trials bikers) it is softer and alot easyer to bleed. With the leaver as high above the brakes I use a botol that I fill with water and skwirt (using a small peice of pipe) into the whole in the leaver then wilst the water skwirts out the draining nut hole at on the brake i skrew the nut in untill no water can come out. I then unplug my botol flicksome water in the hole were the pipe went so theres no air in there atall then skrew that nut in and your brake should be lovley.

The Magura Cult has the best tips for bleeding the brake. Their instructions differ slightly from the official Magura manual.

Plugging one end of the line will create a vacuum of sorts. Just like plugging one end of a straw full of water. I’ll plug one end, put a few drops in the open end to top it off then plug it with the bolt. Then I’ll go back to the other end, undo the bolt, top off the fluid with a few drops, and plug it with the bolt. That seems to do the trick.

The tricky part is making sure no air bubbles get stuck in any hiding places. Sometimes you’ll have to bleed the brake several times to finally get the last of the air bubbles out.

Keep in mind that by horizontal they are referring to how the brake lever is mounted on a normal MTB handlebar. The brake is angled down about 45 degrees or so, just cause that is where it is comfortable to grip. Getting it horizontal just involves rotating it up by 45 degrees or so on the handlebar.

You can manage it all by yourself. But you have to get clever with rubber bands, twist ties, and other gizmos. It’s easier if you remove the brake completely from the unicycle and do it on a work bench. It’s even doubly easier if you can manage to get a second person to assist.

And it’s triply easier if that second person is john_childs.

I know what I wrote earlyer wasnt very clear so I will try and describe it again. This time I have a beautiful, greatly acurate picture though :slight_smile:

  1. Remove both nuts and alow the fluid to drain.

  2. Using a bottle filled with water and a pipe inserted into the highest bleeding hole skwirt water through it so it pases through nice and fast and skwirts out the other end.

  3. Wilst it is still sqwirting skrew the nut in at the bootom still squezing the water through untill the nut is tight. There should be no air in it now apart from at the top.

  4. Remove the pipe and flick a few drops of water in at the top then replace the top nut and your done.

Using water I find is alot nicer than using oil. With water you can bleed your brakes on your uni easily because it doesnt matter when you get water everywere and it is alot softer when using the break because the water is thiner than the oil.

bleeding magura.jpg

I would always take the brake off the uni and suspend it from the ceiling with strings, rubber bands, and such like John was saying. I also constructed some custom bleeding tubes. It helps to play with the brake lever too, while you are doing the bleeding, and flick the lines and parts to dislodge air bubbles hiding inside.

All in all, if you’ve only done it once or twice consider yourself to be a complete noob and have lots of patience with yourself! In my experience it took a while to improve my technique as well as my support gear before I had a reliable, repeatable procedure.

Why go to all the effort taking it off then refitting it when you can do it quickly and easily with it still on your uni? Do you use oil or water? Doing it the way I do you can get it perfect every time and it takes all of about wo minutes.

water bleed

Thanks for that info
I will try that water bleed, looks a lot simpler

That wasn’t my experience; in addition screwing up even slightly meant lots of cleanup since I was working on other people’s unicycles. Oil. Finally, I found that the use of gravity made on-cycle flushing not really effective.

Once I isolated and corrected all the troublesome factors, I found that my brake work was very clean and reliable. Before then, it was frustrating, painful and messy.

Thanks Everyone! This will give me a lot to go on.

'appreciate it!

Cheers.

And if a person rarely uses their brakes except for maybe when he is leaning on his unicycle, how often would said person need to bleed his brakes?

Is the bleeding needed due to fluid leaking out of the system or some other factor?

Once the brake is bled you shouldn’t need to do a full bleed again unless you do something like change the hose (brake line), break a fitting, or break the hose.

Some fluid will eventually leak from around the threads of the fittings. It’s easy enough to just put a few drops of fluid in to top it off without doing a full bleed. It’s not like you have to do a full bleed every year or two just for regular maintenance.

Some bike riders will do things like use water in the Summer then put oil in for Winter. Or use one grade of oil for Summer and a different grade for Winter. But that is being overly fussy and not necessary for unicycle use.

Here’s a past post that discusses using water for Magura brake fluid. I’d be wary of using water though in an area where it may freeze.

(Thread resurrection)
I am now having another problem. If you haven’t read the entire old thread, I have steel braided lines and I can’t get them to work. I bled them last night.

I tried the water and thought I did a good flushing and adding drops of water.

All my connections seem really tight. I went through the steps 5 times last night in a two hour period, each time refining it and thinking I got it right.

I think the place where I may not have a good connection would be on the master cylinder where a barbed fitting sticks up to connect with the crossover line.

Does the barbed fitting thread into the crossover line or does it get jammed up in there and then the (compression?)lock nut is threaded down onto it? I took out the crossover line three times and I wonder if it bored out the crossover line where it connects over the barbed fitting.

Should I cut off a section of the crossover line and restart with a new part of the crossover line or just try to figure out where I am still losing compression?

On the 4th try last night, I got the brake pads to press on the rim when I pulled the lever on the first try, but after 4 pumps, I had lost all friction on the rim. That leads me to believe I am losing compression out of the system…somewhere. Ugggh!

Thanks

Sorry, but could someone please explain to me the purpose of bleeding brakes and what exactly it does? Just PM me a link if there is one - i dont have a clue what is being discussed:o
Thanks:)

Hydrolic brakes need fluid to work, as you pull the leaver the fluid is forced down the pipe and drives the slave cylinders. If you loose fluid or have none in the first place you need to fill them by bleeding fluid through. There cant be any air in the sysem otherwise the brakes will feel spongey and wont be as effective because the air can be compresed where as fluid cant.

Thanks Sparky, that makes it more clearer now:)

Without seeing your setup, it sounds like you “just” have air in the line, Ron. Do what you have to do to flush out that air, reseal without getting more in, and you probably will be fine.

If you’re water bleeding, people I know who’ve done it have done it in a sink or bathtub full of water - not like normal bleeding. ie. take the set off the unicycle completely, undo the hoses, submerge it, work the lever a bit, and then fit the tubes while still submerged and take it out.

Joe

+1. That’s the biggest reason for using water, imho–do the whole flippin’ job under water, see the bubbles leave, and lock it all down tight without the chance of any air getting in.