Back brake problem

Not so much of a problem as a niggle.

The Bindit rear brake has excessive travel before the pads engage the
disc. I've tried adjusting the lever height, I've bled it right through
with fresh fluid using both nipples on the caliper and even gone as far
as fitting a Goodridge line I had kicking around that was the correct
length. Still the pedal needs to be depressed quite a way before the
brake works, but when it does eventally work there's no sponginess to it
at all.

I've stuck my head down and looked at the pads/pistons while pressing
the lever, and they come back a hell of a long way when the lever is
released, which means I have to press the pedal a long way to make the
brake work.

Come on, what's up with it?

 

Mark Olson says...

Bandit caliper seals are rectangular, you can't get them wrong.

If the pistons retract a long way, then you'll need more lever movement
to engage the pads next time round. Stands to reason, dunnit?

 

Muck says...

Already tried adjusting the pushrod, it makes no difference to the pedal
travel, it just adjusts the pedal height. I'm wondering if one of the
holes in the m/cylinder is blocked, maybe a clean out is in order.

 

Mechanically, no idea, but you could get round the problem by having an
inch thick spaz shoe made up for your right foot.

HTH

 

ginge says...

I want it sorting because it's difficult to use the rear brake when
wearing MX boots. Lack of ankle flex in the boots means the rear brake
is redundant at the moment, and I do use it round town and on slippery
surfaces when it works.

 

Muck says...

I'd just go buy a used m/cylinder from a much later bike. They're cheap
enough.

 

Lozzo wrote

Dunno but I have just spent the afternoon catching rays and doing the
deeds that need doing to be able say that my not quite as Bloo as it
used to be Bloo GS does, as promised, now sport a braided steel front
brake hose and the whole episode was entirely painless and issue free.
except when I leaned back to admire my handiwork and forgot about the
cactus.

Maybe it is tired piston seals, they should only give a bit to allow the
pad to just come off the disk and no more.

 

Muck says...

I just did an online search to see what models were fitted with that
m/cylinder. Talk about parts bin specials - it fits 43 different Suzuki
models from 1988 up to 2004. Well, that makes sourcing a recent one a
whole lot easier.

 

It does, but what could make the pistons retract? There isn't anything
interfering with the last bit of movement when you operate the lever is
there? I'm thinking along the lines of the anti-rattle "clip". Also, is the
part of the caliper where the pad sits smooth? If there's a burr on the
caliper or the pad edge, it could be just enough to stop the pad "sitting"
and allowing it to slide back to a more comfortable position.

That's all I can think of anyroad.


--
Beav

VN 750
Zed 1000
OMF# 19

 

Forgive my perhaps obvious suggestion:

possibly the pads are worn?

 

Matt Chapter says...

New pads less than 2000 miles ago, and I've hardly touched the rear
brake becauise it's awkward to operate. They are barely worn in.

 

Muck says...

Same as any early 6V C90 I'd have thought.

 

Beav says...

If the pads were sticking in the caliper then they wouldn't retract as
far as they do. Everything is fine with the pad clearances, but the
pistons retract a long way, and when the pedal is depressed it takes a
lot of travel before the pistons push the pads into contact with the
disc.

New m/cyl is the first choice, then maybe a used caliper if that doesn't
work. Either way, I won't let it beat me.

 

Pip Luscher says...

It does this when staionary.

I've pumped the pistons almost right out to clean them, and they move
freely within the seals.

This sounds most likely. As I said, it'll be easier for me to source a
newer used m/cyl than piss around trying to repair the 60K mile old one
I have.

 

If you're open to wild guesses:

guess number one is that the disc is slightly warped or loose, causing
the pads to get knocked back;

guess number two is that the seals have stuck to the pistons, rather
than letting them slide out to lake up wear;

guess number three (very unlikely) is that there's some sort of
blockage, and when the master piston returns under spring pressure it
draws the pads back.

 

FFS! "lake up wear"?

It's not even as if the keys are adjacent!

 

Loz, have you tried jamming the pedal in full-on position overnight?
This may overcome such stickiness as Master Pip surmises.

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

Mark Olson wrote

That's the puppy.

 

Dr Ivan D. Reid says...

I will try tonight. Anything free is worth a go.

Thanks

 

On Wednesday 19 July 2006 17:57, Lozzo [] wrote in message

Check the reservoir breather isn't blocked, the diaphragm isn't fully
stretched (and so sucking the pistons back) and if it aint them then maybe
the master cylinder needs stripping and cleaning.