I use 3/16" vinyl tubing as you need a tight fit on the nipple to avoid leaks and keep the hose from falling off. Vinyl tubing is quite flexible and with stretch quite a bit. As it ages and hardens I sometimes have to stretch the end using a pair of need nose plier tips as a mandrel.

If you have a manual transmission, don't forget to flush the clutch circuit when you do the brakes.

Duke