You could check the rubber boot that sits between the slave cylinder and the crank case (visible when the sprocket cover and the slave cylinder have been removed) its suppose to stop dirty chain lube getting into the slave cylinder and contaminating the brake fluid but is usually worn through by the chain in a couple of thousand miles.
If you are an engineer perhaps you could design us a version that works
[Edited on 19-1-2005 by S.P]