Cleaning Pneumatics

I've just picked up the pneumatics for Wheely Big Cheese.

These have been sat in a container for the best part of five years and before putting back together they will need a damned good clean. Can anyone recommend some fluids which will clean off the old crap but not attack the seals or attack the aluminium?

Andy

Any propriety engine cleaner like Gunk or you could use paraffin.

Cheers Woody