help needed with brake bleeding

[lms6201]

i seem to be having a spot of bother bleeding the brakes on the trail bike , after a master cylinder rebuild , it,s got lots of push , just can,t seem to get the air out , advise please

[jhovel]

My solution for all bike brake bleeding is to get a long clear plastic hose that fits tightly on the bleed nipple on the brake cylinder. It need to be long  enough for the other end to reach into the master cylinder reservoir.
Attach one end to the bleed nipple, hold other end up high.
Crack bleed nipple and start pumping master cylinder gently.
Watch fluid and air move along hose. Discard any dirty fluid (and top up reservoir as needed.
Once fluid in hose is clean, put other end of hose in reservoir and pump as hard and as fast or slow as you like, until all air ofr foam is expelled and only fluid is criculating.
Tighten bleed nipple and with finger on reservoir end remove hose from bleed nipple.
Either let hose content run into reservoir or discard (or put back in bottle).
Brakes should be as good as they get.
That's how I was taught to do it 37 years ago by the old tech guy at Mayfair Motors, Elizabeth Street, Melbourne, when I first worked on the CB750-4 there....
Cheers,
Joe

[pancho]

have you tried this method?top up the reservoir,leave the filler cap off,loosen the bleeder screw and let gravity do the work ,when you see fluid with no bubbles issuing forth close the bleed screw.[i am assuming this is the front brake with plenty of gravity available.]__ method 2 do the same as above but place your finger over the open bleed screw and lightly pump the lever a few times while allowing the fluid to ease past your finger but blocking the return of air into the bleed screw as you let the lever back. __same applies for the rear brakes where not much gravity assist available.___method 3 devise a way to pressurise the master cylinder reservoir with a low pressure of air, i have had success with this method using an air blaster cleaning nozzle stuck on the vent hole of the lid --careful! use short bursts. if this fails it is possible that the m/cyl. piston is stuck at the bottom of the master cylinder from squeesing the brake lever to hard/far. good luck   cheers wally.

[pancho]

 joe is on the ball i forgot about method 2& a half!cheers wally.

[lms6201]

thanks fella,s  good info , will use , i think mabey after reading i might have a leak  somewhere 

[holeshot buddy]

go to your local animal produce store 
and buy  a plastic syringe
attach hose to end
fill with brake fluid
attach to bleed nipple
take master cyl cap off
force fluid from bottom to top
all air will be pushed out
you can also use it to suck down from
the bottom
this is the best way
trust me i have tried them all, and its quick

[Hoony]

i hate to say this (only joking) but i'm with "Brake Bleeding Buddy" on this one, syringe method is quick and easy.

[lms6201]

SUCkCESS!!!    thanks people , i used the syringe method , with the following variations , couldn,t get one at 6.30 this morn , so grabbing a half empty no gaps (i.e. water soluble )tube , emptying it , using the garden hose to push the piston back out of the tube , flushed it , connected some threaded rod to the piston , one big sucker , the variation was i still had trouble getting fluid through the master so i took the hose of it and put it in a jug with fluid covering the hose end  , bled that with the sucker ( about 30 seconds !) re connected the hose , and bled again done , and fantastic, the gaps tube piston leaks a little bit but gets it done   

[Hoony]

good job done then. 6:30 am this morning

you keen or what !

[pancho]

SUCkCESS!!!    thanks people , i used the syringe method , with the following variations , couldn,t get one at 6.30 this morn , so grabbing a half empty no gaps (i.e. water soluble )tube , emptying it , using the garden hose to push the piston back out of the tube , flushed it , connected some threaded rod to the piston , one big sucker , the variation was i still had trouble getting fluid through the master so i took the hose of it and put it in a jug with fluid covering the hose end  , bled that with the sucker ( about 30 seconds !) re connected the hose , and bled again done , and fantastic, the gaps tube piston leaks a little bit but gets it done   

good stuf aussie engenuity to the fore! cheers wally

[lms6201]

yep . keen as mustard , promised i,d take the girlie , her boy and my two brats for a trail ride today , just fitted new clutch plates and springs and an 87 yz 490 barrell to my wr 500 (had a yz barrell on it but was sloppy on it,s last oversize ) a  wr with a wr top end is just  plain boring ,with a yz top , it is really something else , disc,s , usd kayaba,s  air cooled (don,t have to worry about cooking it due to a stick in the rad or being stuck with a seized w pump ect ) and the 44gallon drum up frount takes along enough fuel for everyone !  but thanks again everyone who contributed to the bleeding issue   

[lms6201]

girlie rode my 370 frontera , with a brrrrrrrrrrrrp up the hills and all sorts of swearing and screaming going down the hills , then i worked out the rear brake cable had let go !!!!! thank christ she kept it in gear