Not sure if it has anything to do with your leak (it may simply be due to poor rebuild quality), but don't use amber or clear power steering fluid in Nissans and most Asian makes unless they call for it. Nissan uses NissanMatic Type "D" ATF (which is the same as genuine Nissan power steering fluid), but Dexron III/Mercon ATF can be used, as well in the power steering system.