In the grand scheme of things; buying vac plastic lines, rubber hoses and elbows are cheep, even from the dealer. From the dealer you'll know you have the correct size not a generic "close fit" and by having replaced them, it'll make it easier to diagnose the cause of a malfunction because you'll have eliminated the vac hose leak problem.

While you're replacing the vac lines, it's an ideal time to test the related components with a MightyVac.