Bleedin brakes

Jon_Pearson

Im gunna bleed my brakes as they feel spoungy and they come in too far as the front brake nearlly touches the grips. Ive got theses front an back http://www.bikeradar.com/mtb/gear/categ ... r-09-34502

and im after some tips and advice on how to bleed them, I can bleed my brakes on my Hornet 600 but ive heard pushbike hydraulic brakes are hard to bleed.

BG2000

Well, the simplest method, assuming you have enough juice in the lever reservoir is to pull the lever against the bar, open the bleed nipple on the disk caliper so that you get some fluid squirting out (with a long tube on the end to prevent fluid squirting on the bike), close the nipple, release the lever, and repeat a few times. With the nipple closed, and reservoir cover replaced, pump the brakes a few times, and if you still have too much play in the lever, you may need to top up your brake fluid (mineral oil in the case of Shimano).

If you really get stuck, or just cannot get rid of an air lock my favourite method is as follows:

Turn bike upside down (so both caliper are higher than the levers).
Loosen lever clamps and twist levers round until reservoir is upright. Remove reservoir covers.
Open bleed nipples and place tube over them with large syringe.
Suck with syringe and you'll see lots of air bubbles.
Keep topping up reservoir with mineral oil while you do this, otherwise you'll just suck air into the lines. Eventually you should get rid of all air bubbles. With a big chunky syringe, you can reallly 'pull' the fluid out with force, which shouldn't allow any air bubbles to remain trapped.

I've also done the reverse, which may or may not be recommended, but it worked for me fine. Basically, put the bike the right way up, and again rotate the levers and remove the reservoir covers. Open the nipples again, but this time pre-fill the syringe with loads of mineral oil and squirt the fluid up into the reservoirs. You'll see bubbles rising up into the reservoir. After bubbles stop appearing, close nipple and replace reservoir cover (expect fluid to overflow from reservoir when you do this, which removes any air gaps). This last method is risky if you've got any dirt in your bleed nipple (i.e. you've lost the flimsy rubber end caps).

nicklouse

Jon_Pearson

they are no harder than any other brakes.

Download the manual and have a read. then find the bleed kit you have and adapt.


remember Shimano use mineral oil not DOT so new bleed kit or clean the old one out.

and the resivoiur is small so many top ups will be needed if doing it the "normal" way.

Jon_Pearson

Thanks BG2000, Ill try the way i bleed the brakes on my Hornet

jairaj

[quote="BG2000"....
I've also done the reverse, which may or may not be recommended, but it worked for me fine. .... .[/quote]

This is how Shimano recommend you do it if your have their special bleed kit. But the kit is expensive and doing the "normal" way seems to work just fine.