viffer brake problem

Just replaced the rear pads in my 2000 VFR800 and decided to replace all
the brake fluid.
I have got the workshop manual and its says to use a "brake bleeder" and
remove the old fluids first completely and then add the new...stuff that
Decided to do what I have always done on every other bike of car I have
had, buy a different colour brake fluid and just keep on bleeding until
it changes colour.

I have bleed all the 7 nipples and got the new fluid out of all of them,
but I have a problem.
30 seconds after I finished bleeding, the rear pedal goes to the floor
and pumps fluid through the system like there is a nipple open, but
there isnt, then over the next 30 seconds the rear reservoir fills back
up by 5mm.
pump the pedal a few times, down goes the reservoir by 5mm and over the
next 30 sec it fill back up by 5mm.....and so one and so on

have I stuffed up the bleeding procedure, or have I got a faulty rear
master cylinder, if it is a faulty master cylinder are they serviceable
items or a throw away item

prolly explain why the rear brakes have always felt like crap too



also, looking for a givi topbox rack for a 2000 VFR800 too, if anyones
got one for sale

Ta

Marty H

 

Yep, they come in pairs. You must've missed one!

 

Does it have the front & rear braking systems linked ?

David

 

Marty H is of the opinion:

The problem with doing that is that you can often suck air back in through
the open nipple if you don't get your timing quite right on the "open, pump,
close, release" cycle. Having a reservoir of fluid to suck back in instead
of air keeps the system air-free.

That's air near the bottom end. What's happening is that there's a big-arse
air bubble in there, and by pumping away you're compressing the air nice and
tight (and perhaps getting a bit of pressure eventually), and then when you
let it all go, the air is expanding and forcing the fluid back up into the
reservoir again.

I'd do a really proper bleed before assuming broken master cylinders (been
there, done that). You can, in principle, rebuild master cylinders, but
it's a fiddly, nasty little job, the spares will cost you a fortune, and
it's most likely not worth it if you can grab one for a few bob at a
wreckers.

- Matt

 

You haven't bled it properly.
Do it again and make sure you have enough fluid in there when compressed.
Your master cylinder is fine.
As for a givi rack I got the rjay's top box and rigged up my own rack
using a rewelded hallmark rack and a bit of ingenuity (Thanks Slej
and Mick who welded the rack.)

http://evilurl.com/butthumpPUSSY

have a looksee

 

the 8th must be the clitoris...I always have trouble finding that!

going to shed......trying the big air bubble scenario now

mh

 

The solution is very simple - buy my Pegaso, then only ever worry about
tweaking with 2 nipples !!

 

I'm sure you'll have no difficulty finding someone to tweak your nipples
Stef, but buying you a pegaso seems a bit expensive !

JL

 

A bloke I know calls his girlfriend "etch-a-sketch". He twiddles her knobs
and draws a smile on her face

 

yup, sure does

air somewhere in the master cylinder thats mounted on the front caliper that
operates the centre pison of the rear brake.....getting there very slowly

Marty