So, got a pile of them on the bench torn down, and rebuild kits sitting nearby.
All are used of unknown provenance and maintenance. Some were pretty stuck.
It's been a LONG time since i rebuilt a master or wheel cylinder. And those were all cast iron. The tilton and wilwood are all aluminum.
some bores have some slight pitting and damage. If cast iron, id use a hone and clean it up. My small enough three leg hone is a 220 grit. Should i for aluminum?
Any other tips?
Wilwood does not recommend honing aluminum master cylinder bores.
They say: "Inspect the wall of the master cylinder bore for scratches or pitting. If scratches or pitting is apparent,
then you MUST replace the master cylinder instead of rebuilding it. Caution: Do not use crocus cloth
or hones on aluminum master cylinder bores. Honing aluminum master cylinder bores will result in
rapid seal-wear and brake failure."
Thanks. I hadn't found that in my research. May explain why i could not find any honing recommendations.
I wonder if its a surface finish issue?
Dusterbd13-michael said:Thanks. I hadn't found that in my research. May explain why i could not find any honing recommendations.
I wonder if its a surface finish issue?
I think I read somewhere that they're clear anodized or something like that and honing cuts through the coating into the softer base metal.
In reply to APEowner :
That makes a lot of sense. Ill rebuild the best, scrap the rest.
Do you like the way that they fit and operate?
Have them sleeved with stainless or brass.
Conventional brake fluid absorbs moisture.
Aluminum bore + steel piston + moisture = galvanic joint that etches tiny pits into the bore surface.
Tiny pits with sharp edges 'bite off' the eges of the seals with each stroke.
Eventually the seals no longer work.
There are multiple places that can resleeve them, White Post is the first that comes to mind. I don't know what it costs compared to simply replacing the master with new. https://whitepost.com/brake-sleeving-rebuilding-services/
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