Brake Calliper re-sleeving

M

Mactriple

Hero member
Location
Wide Bay Queensland
I have two twin bleed callipers that have slight corrosion near the seals that allow small amounts of fluid out. Can the cylinder of a Brembo calliper be bored and re-sleeved? Preferably, is there someone in Australia who does this?
Ian
 
Ian,

Have you checked the grooves for corrosion?  Slight corrosion in the bores will not cause leaking, the rubber seals do all the work. 

I have often found corrosion bulging in the grooves, allowing fluid to pass behind the seal.  Scraping it out and fitting new seals usually cures the leakage, sometimes it doesn't...

Run a hook-shaped scraper inside the grooves, any rough spots are sure signs of corrosion.

piet
 
Best way to go Ian as Piet has suggested. But yes, there is a mob in Brisbane that does good work. Info in my office, so let me know if you need it next week.

Ian

 
FFS, no I didn't say I needed them all......sigh....... As for dremels being for shirt lifters, well there's no one else here to pick my washing up off the floor. What choice do I have but to lift my own shirts up? The kids certainly aren't!
 
I had a look for the caliper for Ian, but it has mysteriously disappeared. I think it must have found its way onto someone else's bike that was in my workshop. Maybe I shouldn't let folks rummage around my spare parts shelves, but what the hell - that's what spare parts are for.

Cam
 
Mactriple said:
Piet,
Thanks for the tip. The brakes didn't leak before being anodised.  I will take a closer look.
Ian
Click to expand...

Course they didn't...

As the corrosion builds up behind the seal, the old seal has time to adapt itself to the bulging corrosion nest.  It is also held under pressure by the piston.  By fitting a new seal over the corrosion, you introduce a slight gap through which the fluid can/will escape.  The seal is not pliable enough to seal against the bulge, isn't meant to either.  Usually, scraping away the corrosion leaves enough smooth surface against which the seal can do its' stuff, the pressure from the piston will further press the rubber into any imperfections that might remain. 

piet
 
mauricejota7604 said:
Hi Cam is your double bleed caliper one of the real early ones I need a right hand side one if you could help (broken bleed screw)3C *1445*
Regards,
M.
Click to expand...

Get it spark eroded out. Cost me $50 and thread and seal is perfect after the broken bleeder is gone.
 
Wrt anodising, it cleans out all corrosion and leaves pitting which seals cannot work against. Can fix by very carefully applying a skim of epoxy into the seal groove.
Cheers
Nick
 
mauricejota7604 said:
Hi Cam is your double bleed caliper one of the real early ones I need a right hand side one if you could help (broken bleed screw)3C *1445*
Regards,
M.
Click to expand...
Burn out the nipple (edm) should be able to find a local shop to do it. I have an edm but shipping would make it expensive
 
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