Do distribution blocks go bad?

[G Force]

Has anyone had a bad Brake distribution block. Can a block get cloged and affect brake performance?
Where can you find replacements?

[Nacho-RT74]

Yes they can damage, specially on O rings because dust and even rust inside ducts... they aren't able to be rebuilt, at least not at home, don't know if some shop is able to do it.

Replacements, yes brass ones, without proportioning valve section. Where... Brake shops I guess... or maybe any parts dealer

[Ghoste]

You might still be able to find a distribution block.  The proportioning blocks are nearly impossible to find.  If the dealer can't get them, try someplace like Fine Lines.