My manual covers the ATAC system, I didn't realize that's what was holding you up. Meybe you have the HPP system, that's in my manual too.
I still don't see any plastic parts on or around the cylinder area, according to my manual it looks like it's all metel levers etc.. It would be VERY helpful to have a few pictures so I could see what's going on. I've never had an ATAC bike before, just the normal. I just did a YZ with the YPVS system, it's similar but has different engineering. I think if I was in your position I would as you said take it apart and just figure it out.
Jordan