bleeding front brakes problem

[Ish]

Hi

On my B1H ZX6R there is too much play in the lever where the lever moves about 1/3 of its total movement before the brakes start to bite. The bike has braided hoses.

Yesterday we tried to bleed the brakes with a pressure bleeder at a friends garage. We used the method of bleeding from the reservoir down and also from the calipers up. We also cracked off all the banjos to get any air that may be stuck.

While there was as light improvement it's still not a solid lever.

I don't know if it's relevant but when we finished bleeding and the pressure bleeder was still switched on the lever was solid but as soon as the bleeder was removed the play in the lever came back.

Could this me a master cylinder problem or am I missing something else?

 

[VoG]

Could be the seal on the MC's cap has had its chips, tho I don't see what loosening the banjo's accomplishes as all your doing is introducing air & knackering the compression washers on the banjo's, which are only good for so many compressions before they stop making an effective seal.

 

[wazza300]

if you pump the lever does it get rid of the free play? solid lever

tried tying the front brake on and leave it overnight then see

tokico brakes are a bit crap tbh,my front brake lever is slightly soft till I pump it

 

[Ish]

Could be the seal on the MC's cap has had its chips, tho I don't see what loosening the banjo's accomplishes as all your doing is introducing air & knackering the compression washers on the banjo's, which are only good for so many compressions before they stop making an effective seal.

Loosened banjo while system was under pressure.

 

[Ish]

if you pump the lever does it get rid of the free play? solid lever

tried tying the front brake on and leave it overnight then see

tokico brakes are a bit crap tbh,my front brake lever is slightly soft till I pump it

Pumping doesn't get rid of the free play.

Will try tying overnight.

 

[wazza300]

tried topping up the res slightly over the top filler line?

could need new res idk

 

[Ish]

Also been advised to blank off brake hoses to rule out whether is a caliper or master cylinder issue so will try this as well.

 

[wazza300]

it could be some stuck or sticking pistons and pushing some more than the others hence the free play till it pushes against the pad

I think they switched to nissin ones later on,which are better allround,might be able to do a direct swap cheap off ebay

 

[Dogbreath]

Sticking piston(s) could certainly cause this. It would force the floating disc to move towards the stuck piston when the brakes are applied.

If it's always been like this, another possibility is an incorrect (piston diameter too small) master cylinder has been fitted at some point.

 

[The Deuce]

get a vacuum bleeder, far better than a pressure bleeder, especially for braided hoses, also if you are having air issues this could point to crap banjo washers.

 

[wazza300]

did you manage to cure it ish??

 

[Ish]

Haven't had a chance to go back to my mates garage yet to narrow down the problem but have found options to deal with either case. If it's MC you can buy a rebuild kit for about £20 and if it's calipers found a place that refurb the calipers including repainting for £144. Mine do need repainting so may take this option rather than a seal kit.

 

[wazza300]

you can paint em yourself

£17 a colour matched can from jawel paints and some etch primer,i did mine on zx10r,i also rebuilt the master cylinder on mine aswell,

seal kits are cheap if you look around on ebay think I only paid £20 odd for the full front set both calipers