The best thing you can do is run the bypass hose to a float tank or holding tank. The reason is when you let off the trigger the water flows out the bypass. That means if you feed it back into the inlet of the pump it will flow in a continuous circle. That causes friction and the water heats up. In turn your packings wear prematurely and so does the unloader. Bad for you good for your service center. That is how they make their money. Now to answer your question, Length does not matter size and rating does matter. Use a hose of equal size and a rating of at least 250psi. If you change over to the other method, just plug the inlet side and run the bypass from the unloader to a tank or even let it run on the ground. Your pump will appreciate it.
