At least according to the warranty info I noticed on the MCP35X as I was browsing around aimlessly (things you do when not feeling too well):

Important warranty information:

Users are advised that disassembling the pumps, including for the purpose of upgrading the housing, automatically voids our warranty.
http://www.jab-tech.com/Swiftech-MCP...p-pr-4750.html

So this in mind, if you aren't changing pump tops how are you supposed to properly clean the pump?

Doesn't affect me right now since my MCP355 is probably well out of warranty now and I've changed the top on it anyway, but it does make me wonder if I technically voided the warranty on it as soon as I opened it up to clean it when I got it.