Mot fail on back brake so new master cyl repair kit and new pads and calipur seals to go in though the LAverda Guru says they were always marginal even when new as the master cyl volume was right on the ragged edge of having enough volume. suggested I FIND A NEW TESTER. He is prob right but happy to rebuild it anyhow. awkward getting the calipur off as its fowled by the swinging arm and the shock which was easier to remove rear wheel loosened and chain off allows just enough room to get the bolts off the calipur mounting CAsting. master cyl removed next and milliaons of questions from my grand daughter who knows as much about rear brake discs as is good for a five year old.
shock off and calliper and master cyl in this shot, also rear set disconnected from actuator just visible. going to try bleeding it on the bench and replace the piston seals on both wish me luck
I quite enjoy rebuilding brake systems, once you get the hang of it it's very straightforward.
The most important part is always be prepared
- have enough of, the right kind of, brake fluid
- if at all in doubt spray it all down with some penetrator (avoid pads if going to reuse) as stuck/sheared bolts are a pain, especially those bleed nipples
- have lots of rags, maybe some paraffin to spray on and dilute any errant brake fluid
- don't do it on a sunny Sunday afternoon if you have to use the bike first thing Monday. You don't always -need- to replace seals but it's perfectly possible to tear a useable one, getting it out for cleaning.
I concur, rear brakes on the 2 I've owned and a few more ridden when newish were dire, you could almost stand on the pedal and it would have little retardation effect
rather unfairly the tester wnts it to be able to lock up the rear wheel, it never did as mentioned by many. new mot tester may well be the only option.
rodbargee wrote: ↑Mon Jun 14, 2021 6:41 pm
rather unfairly the tester wnts it to be able to lock up the rear wheel, it never did as mentioned by many. new mot tester may well be the only option.
He's obviously never tested a Tuono. The rear brake is pitiful even from new.
Quite often with road bike rear brakes there is a mismatch between caliper piston size and master cylinder ratio. From this chart a figure in the 12-14 range is desirable for a decent stopper. It's not hard to find the stock set up figure may be much less.
Dicking about with different pads can sometime get an acceptable result without going down the m/c rabbithole.
He's obviously never tested a Tuono. The rear brake is pitiful even from new.
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On mine I take it off the mount and hold it above the reservoir. Southern Cross also drilled out the master cylinder slightly. Never failed an MOT yet.
Ok then caliper rebuilt with new seals grease and dust covers (pistons teflon coated No scratches ...Master cyl new piston with seals and a spring successfully installed with crimp braided hose comprehensively bled on the bench and the bike no air coming out still piss poor as the laverda specialist said it would be any tips for getting a better peddle at home I just have an easy bleed. no leaks anywhere just pitiful performance the laverda-nista recommend an R6 master cyl conversion. but I'd prefer to get it to work as standard, Have turned the calliper upside down and back to front to make sure Ive got all the air the received wisdom is that the master cyl has too small a volume to be effective ( new pads By the way they do grip the disc but are in no way effective. mot fail still
rodbargee wrote: ↑Wed Jun 23, 2021 11:34 am
... the received wisdom is that the master cyl has too small a volume to be effective ( new pads By the way they do grip the disc but are in no way effective. mot fail still
Hard to get an effective work around for that problem.
If retaining the stock appearance of the bike is important to you and the rear brake not so important,what about using the R6 m/c to get it through the mot,then revert to stock when you get your ticket?
rodbargee wrote: ↑Wed Jun 23, 2021 11:34 am
... the received wisdom is that the master cyl has too small a volume to be effective ( new pads By the way they do grip the disc but are in no way effective. mot fail still
Hard to get an effective work around for that problem.
If retaining the stock appearance of the bike is important to you and the rear brake not so important,what about using the R6 m/c to get it through the mot,then revert to stock when you get your ticket?
