37 Years.

That's how long I've been riding bikes, & in all that time I've never
had to replace any brake seals. But now I do. Any tips? They're Nissin
twin-pots if that makes a difference.

 

Invest in a sachet or two of red rubber grease and smear that lightly
into the grooves after cleaning them out with a Dremel and as fine a
wire brush as you can get away with. From there on only use brake fluid
as a lubricant.

 

I had a bit of a baptism of fire when I managed to pop a piston out of
a Tokico 6-pot last year. Rebuild went fine, got 'em very clean,
pistons all went back in with a bit of brake fluid as lube. Took a
while, mind.

 

Use the brake lever/pedal to push the pistons out before you disconnect
all the plumbing. Or use an airline to blow the pistons out afterwards
but be careful.

Take a bt of care when you're pushing the pistons back in because if
they have sharp edges they can slice a bit of seal off. DAMHIK.

+ 1 Wot Lozzo says - I've got a big pot of red grease around somewhere
if you need any.

 

I cleaned them all up earlier, greased the pins & slid the pistons in &
out a bit to see if that helped, but no joy - I've got a bike with a
parking brake.

They seem fine, other than having Nige's Knob Syndrome[1]

A who-what?

So no jiz then?

[1] Refuse to slide back inside.

 

Think I've got some of those somewhere.

Ah good, so there is a need for power tools then.

 

That was plan A.

And that was plan B.

Think I've got some sachets, but thanks anyway.

 

What about that red stuff?

 

It's very unusual for Nissins to need a rotary wire brush because the
bodies of the calipers seems to be hard anodised throughout on all the
Nissins I've worked on. If they were Tokicos I'd be buying three or
four wire brushes before I took the things apart because you know
they'll be full of alloy-fur and grunge.

 

On Sun, 03 Jan 2010 22:40:39 +0100, Simon Wilson

[...]

A grease gun should also work and there's less chance of any colourful
mishaps then with pressurised air. ;-)

 

THe colour in question being red I expect

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Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

 

Silicone grease is a suitable lubricant, its water repellent and seals
against corrosion. Maplin usually stock it, as should any electronic parts
supplier.

For floating calliper slide pins and any other moving parts not in contact
with any braking system rubber parts - finish line Teflon fortified bicycle
grease works wonders. It used to come in 100g tubes for about £6 but they
changed it to a more expensive aerosol dispenser, last time I bought any was
a 1.8kg tub for about £35.

 

A few G-clamps can come in handy if you have multiple pistons.

Pump the brake and see which piston gets away the free'est, G-clamp that one
back in so you can pump out any pistons that are less eager to move.

 

It's just about coarse enough to polish aluminium but as a close
finisher it's unbeatable. We used to use it for fine tuning 3D wing
section leading edges when I worked in the wind tunnel industry and
everything had to be spot on.