hydro brake hose re-install question, new olive or not?

[eddief]

i will be changing Di2 shifters on one my bikes soon from Ultegra to GRX. first time dealing with hydraulics at all. have watched every video so i get the concept. should not be changing hose length and will be reusing existing hoses. should be merely undoing hose from lever, running hoses through drilled carbon bars, and reattaching to new levers.

do i need to replace the olive or can i use old one?

any other dork advice? i have full bleed kit ready to go too.

[P K]

New olive and barb every time, you'll need to cut the hose shorter (the length of the barb)