Bleedin' Bleeding Brakes

[exBanditOwner]

anybody gor any brake bleeding tips. because i cannot get a satisfactory lever. don't really want to get new seals and fully overhaul the calipers but it's looking that way.
i've read the manual and followed the procedure to the letter.

currently got the level pulled tight and held with zip ties will see how it is tomorrow

[pete fairbairn]

Hi be carefull with what you are doing,leaving system under presure means air is absorbed into fluid it doesnt mean its gone.I have found back bleeding system from nipples up into reservoir works,i use a car clutch master cylinder to do it Do not get fluid on plastics etc it will damage it.You could buy a pump from scrap yard or Halfords???

[viper]

this question about brakes has come up loads of times on here, so im due to do mine again next weekend so I will post a video of the bleeding process. People are convinced their is something wrong with their bike but its ALWAYS the fact that they are not doing it correctly . its a different process to doing cars and it does take a while .

[virginiajim]

Hi be carefull with what you are doing,leaving system under presure means air is absorbed into fluid it doesnt mean its gone.I have found back bleeding system from nipples up into reservoir works,i use a car clutch master cylinder to do it Do not get fluid on plastics etc it will damage it.You could buy a pump from scrap yard or Halfords???

You said 'nipples'.   

But I've never had an issue with mine (knock on wood)..fronts or the rear.  I do use the EZ Bleeder one way valve, though.   The clutch is the one that can cause untold amounts of grief.

[exBanditOwner]

hello. please enlighten me as to what i'm doing wrong.

[viper]

hello. please enlighten me as to what i'm doing wrong.

I cant comment on what you are doing wrong as I don't know what you have done, explain your procedure? all I can say is that ive seen a dozen or so members come on here with brake bleed issues convinced there is something wrong , bit of advice and then they always manage it .

if you developed problems without actually doing something to your brakes then maybe you do have a seal issue, if you have developed problems during routine maintenance its your procedure 

[exBanditOwner]

new discs and pads fitted. pumped pistons out a bit. cleaned up and pushed back in. the pistons did not come out.

pushed pistons completely back in.

flushed out fluid with new fluid and bled brakes according to the workshop manual. it's annoying me because i am competent.

[viper]

well the simplest way is to use a clear length of hose attached to the nipple and submerged into a jar of brake fluid ,( I also draw some fluid up into the hose to create an almost vacuum trap )  1/4 turn on the nipple and then keep pumping slowly but surely , it can take 3 or 4 reservoir amount of fresh fluid before you get all the air out. If you have got air in then the reservoir must have run dry at some point .
the common  mistake newbies make is bleeding the system like a car , pump,pump pump, release nipple, with a bike its nipple released and continual pumping, as I said you can use a complete bottle of fluid in getting all the air out . you think the air is all out and then 20 pumps later a shed load more bubbles appear.

slow and firm

[exBanditOwner]

thanks Viper. That was the technique i was using. however just to eliminate any doubt, i have just bled through another litre of fluid. no bubbles. no difference. i took the calipers off and manipulated them about tapping them etc. no different.

And chance air has gotten in to the ABS pipes and lodged there? the manual doesn't mention bleeding this.

[viper]

thanks Viper. That was the technique i was using. however just to eliminate any doubt, i have just bled through another litre of fluid. no bubbles. no difference. i took the calipers off and manipulated them about tapping them etc. no different.

And chance air has gotten in to the ABS pipes and lodged there? the manual doesn't mention bleeding this.

what do you mean ABS pipes? I thought the abs was an electronic sensor and a metal ring around the hub?
ive just watched some clips on ebay and some take off the caliper and insert a block of wood to replicate the disc and then rotate the caliper during bleeding to help the trapped air out, they also rotate the master cylinder on the bars  to ensure the hold in the cylinder base are at an uppermost point ,

id still do the overnight cable tie method regardless of previous post , it does work

[exBanditOwner]

abs pipes. the hydraulic pipes that link the abs pump to the caliper.

[viper]

to be honest once you get into ABS then im not sure what im talking about but my understanding was that its all on the same system for bleeding , all you have to do is bleed at the nipple , its one line from the m/c to the caliper going through either a pump or valve that releases brake pressure when the abs signal command it

cant help you any further but im doing a complete fluid change at easter so maybe I will find out further , although ive done it on this bike before and loads of others

[exBanditOwner]

i'll give it a good thrashing tomorrow. that normally fixes everything.

thanks for your suggestions

[viper]

i'll give it a good thrashing tomorrow. that normally fixes everything.

thanks for your suggestions

just had a look at the workshop manual and it does have a hydrualic unit  under the tank in front of the seat where all the brake pipe unions meet up, is says nothing about a bleed valve there or indeed bleeding it, under installing a new hydraulic unit it just says  to do a normal brake line / caliper bleed .

[exBanditOwner]

yes i saw that too. just doesn't seem right to me. the ABS unit pipes are Tee'd into the line between the master cylinder and caliper and run upwards back to the pump. If air gets up and in there no amount of normal bleeding will bring it back again but it will give a spongy lever.

i'll activate the ABS a few times tomorrow see what that does.