pistons and slime block are not passing energy red stone torch and red stone block !!

I was making a red stone robot, as it did in minecraft ( 1.7.10 ) when finished , something was wrong it was not working , I see if something was wrong , that was when I saw the slime block and piston It not was transmitting energy through the red stone torch and red stone block ! Question on the piston not eta transmitting power to another piston , among other electrical object ( applies to the piston clingy too) .