how du u bleed disc brake ?

[vince]

the diameter of the piston on the master cylinder can have a big inflluence on the amount of travel in the lever.the smaller the diameter the more travel .

[rbgaz]

shame they dont hav aduster screw on the lever

[rbgaz]

am at my wits end on this, on the verge of giving up on lamys !!!
i hav now replaced the mc and the calliper hav the biggest mother of syringe !! hav tryed pumping up and down its worse than ever ffs what the f@@k am i doing wrong !!!

[storkfoot]

............... take the top off the master , go get a big syringe a short length of pipe to fit the bleed nipple , put a ring spanner on the nipple then the hose , open the nipple then push the fluid back up the system it'll work its way up and fill the master , close the nipple off unclip syringe empty the master then repeat a couple of times job done , very quick and easy , ...............

Last 3 or 4 times I've done it, I've done this, more or less. If you have a decent size syringe then you can fill the whole system from one filling of the syringe but make sure the bottle of fluid has been sat still overnight ie no bubbles in.

First attach the pipe to the end of the syringe and open the nipple on the caliper (keep your ring spanner on the nipple, you'll need it in a minute)

Then, fill the syringe gently and slowly. When it's full, tip it back and take it over to the caliper. Then depress the plunger in the syringe and get the fluid just to the end of the pipe. Place the pipe over the nipple and, again, gently and slowly, press the plunger and fill the system until the fluid in the master cylinder is almost covering the sight hole (this does depend on the angle your handlebars are positioned).

Now's the slightly tricky bit. Close the nipple with the ring spanner. Then, keeping your left hand on the brake lever, and your right hand on the ring spanner, you need to pull the brake lever in gently a few times, at the same time as opening the nipple and pushing a little bit of the fluid out. You should feel the lever becoming harder to pull in until it's right.

Like anything, it takes a bit of practice but when you've done it once, it's dead easy

[Andy Pickering]

If anyone would like to add to this thread from there own experiences from bleeding disc brakes it will help build a quick reference catalogue which will help all forum members..

For anyone still struggling with bleeding front brake check out this link:
http://www.smellofdeath.com/lloydy/hydr ... brake2.htm

[Toddy]

............... take the top off the master , go get a big syringe a short length of pipe to fit the bleed nipple , put a ring spanner on the nipple then the hose , open the nipple then push the fluid back up the system it'll work its way up and fill the master , close the nipple off unclip syringe empty the master then repeat a couple of times job done , very quick and easy , ...............

Last 3 or 4 times I've done it, I've done this, more or less. If you have a decent size syringe then you can fill the whole system from one filling of the syringe but make sure the bottle of fluid has been sat still overnight ie no bubbles in.

First attach the pipe to the end of the syringe and open the nipple on the caliper (keep your ring spanner on the nipple, you'll need it in a minute)

Then, fill the syringe gently and slowly. When it's full, tip it back and take it over to the caliper. Then depress the plunger in the syringe and get the fluid just to the end of the pipe. Place the pipe over the nipple and, again, gently and slowly, press the plunger and fill the system until the fluid in the master cylinder is almost covering the sight hole (this does depend on the angle your handlebars are positioned).

Now's the slightly tricky bit. Close the nipple with the ring spanner. Then, keeping your left hand on the brake lever, and your right hand on the ring spanner, you need to pull the brake lever in gently a few times, at the same time as opening the nipple and pushing a little bit of the fluid out. You should feel the lever becoming harder to pull in until it's right.

Like anything, it takes a bit of practice but when you've done it once, it's dead easy

Thats the method i use as well after some dealer advised me to fill from the top a few years ago and keep pumping till it gets hard !!!!!!!!!

[Fenian Mick]

as Johnny stated earlier in posts........ pump it up from the caliper. Syringe method works great, even done it with an oil can and putting small amount in the reservoir to start with...........dont waste your time pumping from the top.

[yellow peril]

After many frustrating hours with this problem, i was lent an industrial vacum pump as used in garages which works instantly. My garage friend assured me you can get 'budget' versions which are more than ample for our purposes! i found this on on ebay and it works a treat, fully bled front caliper in 10 secs!!
I think most chaps in our club have borrowed this at some point, expensive some may think but i have used on the wifes car etc....

http://cgi.ebay.co.uk/Motor-Cycle-Hand- ... 2a0ad4c94b

[gpsteve]

i have just fitted new brake and bleed whith syringe how much travel sould i have at the brake lever, as brakes start to bite about half way but i can pull leaver all the way to the handel bars is this right

[joespeed]

i have just fitted new brake and bleed whith syringe how much travel sould i have at the brake lever, as brakes start to bite about half way but i can pull leaver all the way to the handel bars is this right

by the time you have pulled the lever all the back you will be over the top of the handlebars,take it for a spin and try the brake out,you may have a little air in and cracking open the nipple whilst pulling the lever should release all the trapped air!