if it's internal square then either 1/2 or 3/8 extension/ratchet will do it, if it's an external square then you could get some square bolt sockets (inside looks like a star).

 

Well the master cylinder had no fluid in it today not sure if there is a leak but refilled that and checked on the slave cylinder and such. It was better after some minor tweaks and refilling the master so I'll just continue to watch after it.

 

Hmmmmph! Thought those were mechanical linkage clutches.....Learn something new every day!

 

Well the fact is the fluid had to go somewhere, it doesn't evaporate, and wear doesn't drain a MC, so you need to find the leak. If the MC was truely empty (no fluid in the rez.) as opposed to being very low, it probably took on some air and needs bleeding.