Back Brake - Replaced parts and still not working

Where'd you live?

dazthephot said:

Where'd you live?

Click to expand...

Liverpool mate, if you're local I'd be happy to help.

If not the method I use is a big length of pipe on the nipple, crack it open with the pedal closed, shut the nipple then release the pedal.
Once I've done this a few times to get fluid in the pipe (usually looped round the bike) I just open the nipple and give it beans on the pedal (line upright over the bike means no air just fluid going back in the caliper)
If this fails caliper off and the same process.
If that fails (hasn't yet) I use a 50ml NG syringe as a vaccum bleeder and either suck, or push fluid through the system.. this has never ever failed even on a set of tokico 6pots with the mudguard loop in the lines! (TL1000R)

Thanks mate that's a very kind offer I appreciate it. I'm over in Hull so if I struggle ill give you a shout.

Th3Judderman said:

This intreagues me, I'd love a crack at one of your bikes 'cos I can bleed mine up in about five mins and it works flawlessly for a year each time.

Click to expand...

It's a piece off piss to get a decent brake with a really good 'pedal'.
I've been bleeding brakes for over 40 years, and never had a problem like this before.
Not all bikes are affected....some you bleed once and that's it, job done....I've done a few of them like that, they're great to do, and they're no problem.
But they're NOT all like that.

Like I've said, I can get the perfect pedal, solid as you like, with a perfectly working brake...EVERY time.
Problem is.....the bad ones last a few hundred miles, and then start to go 'off' (soft pedal) again.
They deteriorate until there's NO brake.
Hang a weight (5kg) on the pedal overnight, and you're good to go again....but only for a few hunded miles...then it goes soft again.
I've heard that if you grind up a tablet of Viagra and put it in the fluid, you'll actually get a firm pedal.
Seriously, nobody knows the answer to this, it's nothing to do with heat (that's been proved) my theory is cavitation, but that can't be proved, so it's just one of those quirks.
I got bored, fitted rearsets (which mount the m/c vertically) bled it (5 mins) and haven't touched it since.
That was nearly 3 years ago.
Incidentally, mounting the m/c horizontally should actually have no detrimental effect, nearly all car m/c's are mounted horizontally aren't they?
I'm currently in the process of fitting a rsv4 m/c with built in reservoir to tidy things up, the fluid is a bit tired too, so could do with swapping. I use a Mytivac or reverse bleed as required.

Your mission..... should you choose to accept it.....is to fix the problem.
This message will self destruct in 15 seconds

Ha ha like it, I accept!
My pressure as it is has held for 8 weeks around 400 miles.
I'm gunna do it again hopefully this weekend with fresh brake fluid. It goes to bed for the winter end of sept so if its ***** when next spring comes there will be a shiny set of rear sets going on.