More front braking woes

Okidoki,
My nissin master cyl, brembo caliper, goodridger hosed front brake has been playing up. Very light lever pressure can get the lever an inch or so away from the handlebar before braking kicks in. However, for normal use its two finger, no-problem, short lever travel, all fine.

I've changed the master cyl plunger with the wemto kit, bled the brake through and done the cable tie at night on the lever thing (to get on very small bubble of air) and cleaned the pad pin too. Still have same issue so anyone got any suggestions?

cheers


muttley1

Disc/pad contamination?

Have you taken the pads out to see the pistons react to the lever pull?

Slide pins on the caliper binding?

Might be. However, all parts sprayed with brake cleaner before reassembly, not a grubby fingerprint in sight!

Id probably start with removing the pads and watching the pistons as you slowly pull the lever to see how well they are moving as that should give you an idea on the MC and fluid effectiveness.

Just remember not to go mad and pop them out a bit of hard plastic or something should be able to press them back in but clean any dirt on the piston first to save getting it past the seals.

HI,
pistons cleaned before assembly, I did move them out a little for this, no issue found.

Off to garage now to check for any air after another night with cabletied on front brake..

And might be onto something. Having changed the banjo washers to oe Goodridge ones and re-cleaned the pistons etc I noticed that the little metal widget that sits in the bottom of the master cylinder resevoir had come adrift from its recess.

Best put it back in then so anyone know which way up it goes? There are 3 little prongs, do they face downwards or upwards in the small cup over the hole above the piston?

Haynes is no help, just shows exploded diagram of Nissin caliper.

cheers


muttley1

Quick question, why have you got a Nissin master cylinder and a Brembo Caliper? Are these two components even compatible and could this be the root cause of your braking issues?

The bike came with that set up, I suspect many did and all works fine, no compatability probs. I also have goodridge brake hose.

Btw, worked out the little widget issue, found it on cbr1000 parts diagram. Brakes bled again and lever currently bungeed on so will see how it is tomorrow.

muttley1

I put on goodridge branded banjo washers just because I had them handy and some improvement. The bike stops just fine and lever travel is ok. It passed mot so can't be all that bad. I did tell the tester too.

Next (and last) option will be to clean the master cyl itself and see if there's any gunk in the barrel where the plunger sits in case the return spring is getting fouled.

muttley1