Hydraulic Brakes
 

Can anyone tell me how to fit a new lever to my bike which has hydraulic brakes. If I disconnect the old one, will I loose all the fluid, will I have to bleed the brakes afterwards and if so how do I do it?

I am from the UK and I have an Onza T Bird trials bike

Hi, if it was me, I'd drain all the fluid and just put new stuff in - its always better to work 'cleanly'. It's just a case of disconnecting the hose and putting it in the new brake lever. Just go to the manufacturer of your brakes website and try and download a set of instructions, that way you'll be working through a set of specific steps. They should also have little tricks to help you.

Is it possible to have pneumatic brakes?

I want air brakes so they make cool 'PFFFFFFIIIISSSTTT' sounds when you release the pressure., Like a bus!

Simon

o_o You do realise that those busses use a compressor to form air pressure?

And in theory it could be done. The pneumatic thing, that is. In fact, it would make more practical sense than hydraulic. :) just carry a 'brake pump' around. The only thing is that gasses compress.

No.
http://img127.exs.cx/img127/5893/354crackpipe.jpg

Are you talking about HS-33s? Or rim brakes at least?
You should be able to change the lever without rebleeding, but you will have to top up the fluid. Just unscrew the hose fitting into the lever with an 8mm spanner, then screw it into the new lever. Try and keep the hose upwards so as little fluid as possible leaks out. Then once it is screwed into the new lever, unscrew the bleed valve (the little screw going into the lever just above the hose coming out, and top it up with some Magura royal blood, or water with a bit of antifreeze in. Never Dot4 brake fluid.
You should be able to get it pretty good this way, maybe not perfect without a full bleed, but pretty good at least.
Cheers

Yeah but I thought of that too lol

There will be a counter weight on the back wheel which will push a push with each revolution and store compressed air in a canister below the rider (Where you usually put those crappy water bottles).
Then the brakes have lots of supply! But if you are free-wheeling down a hill and come to a road your screwed lol I'll work on that part

Simon

If you want an air brake on a bike use a air piston that has a release valve that opens and immediatly closes at tdc and bdc. As it strokes up the valve is closed and compression builds slowing the wheel. At tdc the valve opens releasing the compressed air and then closes allowing the cylinder to draw compression to bdc where the valve will open and let atmosphere back into the cylinder to be compressed on the next cycle. When just riding along the valve will be held open to eliminate the braking effect. This way you do not have the extra weight of a storage cylinder or the system drag while you build up pressure.

Why not? With some thought and cleverness, it could be done without adding a whole lot of weight to things. Just because something hasn't been done (side to everyone else: it hasn't, had it?) doesn't mean it shouldn't be at least tried. How else do we make advances?

I didn't say it was practical; I asked why not? ;) Heck, think about it - if someone figured it out and had it on their bike, it'd be a one-off and *totally* unique! Just for that it would be the envy of geeks everywhere!

Hydrolics would be cool! Maybe not for marketing but a personal project :D

Where would the pressurized air source lay, and how won't it effect the frame's strength and how will you get new air in since air brakes can't run on used air?

You're sooner to develop steam brakes before air brakes for a bike. Shimano tried Air powered shifting, didn't go over too well. Alot of punctures in the air hoses.

My brakes are HS11's and please could you advice me on how to bleed them.

The HS-11 brake levers do tend to break easilly. At least more easilly than HS-33s. Look on the Magura website (www.magura.com), click on bike components, and then brakes, and they have a full manual on how to bleed them. I think it is also in the manual given with new breaks. I'm not sure whether or not you actually read my last post, but if you're careful, you shouldn't need a full bleed.
Cheers

Thanks for the info will give it a try

I think that you mean pneumatic, not "Hyrdrolics". pneumatics is to do with air, hydraulics is to do with liquids. :eek:

NOTE: not trying to be an a**hole, just felt like correcting