oh, ok.
Stangly enough, it is not the same brake line used for a 2005 XB12S and a 2010 XB12SX for exemple.
According to this pdf : http://www.ukbeg.com/pash/Buell%2020...ccessories.pdf
Here is which brake line you need for ZTL2 :
Brake line Model 2008 2009 2010 XB12S H1531.8AE N/A N/A XB12Scg H1531.8AE ZTL-2 is stock ZTL-2 is stock XB9SX H1531.8AE H1531.8AE H1531.8AE XB12Ss H1531.8AE ZTL-2 is stock ZTL-2 is stock XB12X H1531.4AK H1531.4AK H1531.4AK XB12XT H1531.2AV H1531.2AV H1531.2AV XB12STT H1531.4AN n/a n/a