Thank you for all your tips.
My graphtec working but not like it was, but I undestand it will not working like it was at the beggin.
But I would like to clean it and grease it let me show you some picture of the beast :
https://www.dropbox.com/s/xum077e4qpg7ohw/Photo%2012-10-2015%2015%2007%2032.jpg?dl=0
https://www.dropbox.com/s/rf3w8pesdvvoegc/Photo%2012-10-2015%2015%2007%2016.jpg?dl=0
Thanks