Tw*t-proof guide to brake bleeding?

As header. 1400 failed it's MoT today as both sets of brakes were very
spongy, with too much travel. Pads are fine so almost certainly air in
the system, I are told. ( He was fine with the exhausts,which was a
result ) .

So, I did a quick google to see what UKRM had previously said on this,
and got this from TOG in Feb 03:

++++++++++++++++++++++++++++++++++++++++++
To bleed the brakes: attach piece of bleed pipe to bleed nipple. Put
other end of pipe in glass jar.

Pump lever half a dozen times, and then pull in. Without releasing
lever, open bleed nipple.

Close nipple. Release lever. Pull in lever. Open bleed nipple. Close
nipple. Release lever. Pull in lever.

And so on and so on, remembering to top of the fluid reservois as you
go. When no bubbles come out of the pipe and the lever feels firm, it's
done.
+++++++++++++++++++++++++++++++++++++++++++

Now, that seems easy enough. Just a quick question - before I do this,
do I remove the appropriate cylinder cover for the brake I'm working on?

Also, is the pipe/jar interface just to stop brake fluid hitting the
paintwork?

Finally, is this the 15 minute job it suggests or could I be there for
hours deopending on amount of air in system?

If it helps, when I press the rear pedal as is I hear a slight knocking
sound - would that be the pistons trying to move out?

Ta in advance, as always.

 

Dave Jennings wrote

How long is a piece of string?

I feel it really is a two handed job, unless you are either proficient
or have Gadgets.

Even then, for some completely unknown reason, bike brake system /can/
be a right bastard to bleed, sometimes, on some bikes, but not always.
It is a mystery.

 

If there's no valve on the tubing you're using, you'll need jar partially
filled with brake fluid (to stop air being sucked back up into the system).

No - only the reservoir cap and bleed nipples are opened during the process.

Where else is the fluid going to go? Plus see above

It's much quicker and easier if you have someone to help you (pumping /
holding the level while you do the bleed nipple, and make sure all the
tubing stays connected (it has a nasty habit of popping off the nipple when
under pressure). Even so, allow at least a hour if you've never done it
before.

Some other important tips:
- Don't forget to leave the jar of fluid to settle for 24 hours beforehand,
or you'll be putting aerated flud into your system
- DO cover all paintwork around the area - you _will_ spill some brake fluid
- Dispose of any leftover fluid from the new jar after you've finished both
brakes - it doesn't keep.

 

Dave Jennings wrote:
[snip]

Yes, otherwise you won't be able to top up the brake fluid. If the
fluid is dark brown it is worth flushing a fair amount of fresh fluid
through the system.

It also stops it from pissing all over your garage floor.

This appears to be your first time,I would put aside a couple of hours
to make sure you do it right, do you want a hand?

Might be, might not.

--
Martin:
"For a minute there, you bored me to death."
VTR1000 Firestorm
TDR250 http://ukrm.net/BIKES/Yamaha/tdr250.html
martin dot smith nine zero three at ntlworld dot com

 

SNIP!

The problem with trying to make anything "twat-proof" is that twats are so
damned ingenious........

Tony

 

Martin yik-yakked:

Nice and clear, all replaced fairly recently, ta.

Ta for the offer. Let me have a try first, and if I'm stuck, then
expect a shout and some beer tokens!

Ooh. Very coy!!

 

TMack yik-yakked:

True. I get up early to connive devious ways of beating twat-proof
methods.

 

Monkey yik-yakked:

Great advice there, ta!

 

If you close the bleed nipple before releasing the lever, then air can't
get sucked in....

That it does.

What he said.