tuono rear brake problem

[maz]

My tuono rear brake just past its MOT by 1%, Its always been rubbish, Having read various threads it seems a common problem. I've tried bleeding it every which way but with limited success, its better for a couple of weeks but still poor, good job I hardly use it really. My question's are, could you use a falco rear set & brake set up ?, I know its possible to use the set up from the RSV4
but can be difficult to source at sensible cost.
Would be interested to hear anybody's idea's Thanks.
Going to try a new 13mm master cylinder first to see if that improves things.

[fatboy]

Im not sure how similar the falco/ tuono set ups are but from my own experience with an early falco...
The back brake has never been very good, a bit all or nothing but has never been an mot issue.
Bleeding it up has always been difficult because when in situ the bleed nipple is a fair bit lower than the banjo bolt, the air always wants to rise to the banjo rather than vent out through the bleed nipple.
Please note that not all falco rear brakes are crap and there may be some owner stupidity to take into consideration

[randomsquid]

I can't see where using the Falco set up would gain anything. The caliper is the same but underslung which makes it a bitch to bleed.

I bought an rsv rear master cylinder when I was piddling about with rearsets. More or less the same part, same diameter but either the inlet or outlet was positioned differently, don't remember now. The actuating rod on the RSV is quite a bit longer as suits the peg and linkage set up.

From memory the RSV set up is more prone to getting cooked but they're both shite. I use mine occasionally just to get the rust off.

If it helps the RSV one in the shed owes me about 20 quid including postage if you want it to play with. It's missing the plastic screw on cap on the reservoir because I gave that to a guy at work with a 650 scarver when his was pinched or fell of.

[Dalemac]

There are various methods to ge tit bled up right. I've always had success with reverse bleeding, personally. I've actually locked up the rear wheel on occasion.

That said, I've just bought some AP rearsets (I've been wanting these for literally years), which relocate the mastercylinder, which should help with bleeding everything up again.

There is an uprated rear brake master cylinder available from Brembo. From a 12mm to 14mm piston. Probably improves braking performance quite a bit, but I've no idea if anyone actually knows about this or has tried it out.

[fatboy]

I'd be interested to hear more on the 14mm bore master cylinder.
Cant find one on ebay.
TBH I would be happier if my rear brake worked with some kind of subtley as its everything or nothing, not cnofidence inspiring

[flatlander]

I think AP replaces the rear or can do when they fit their rearsets squid would know best

[Dalemac]

I'd be interested to hear more on the 14mm bore master cylinder.
Cant find one on ebay.
TBH I would be happier if my rear brake worked with some kind of subtley as its everything or nothing, not cnofidence inspiring

I've got the brembo part number in a catologue at home. I'll dig it out and have a loo at the weekend.

[randomsquid]

I think AP replaces the rear or can do when they fit their rearsets squid would know best

I'm still using the standard Falco one with mine, changing it wasn't mentioned as an option.

[maz]

Thanks for the offers and advice, I have had the rear master cylinder in bits to check bore (11mm) etc all look good with no leaks, thought I'd do a repair with new parts from the gutsibits site, they have some brembo rebuild kits but unfortunately it was not the right kit so sent back. So going with a new 13mm rear master cylinder, will see how that goes when it arrives and I fit it.