Originally Posted by
Endopotential
You've already got the answer right here. The more old parts you replace, the better. On my bike, turned out that there was a tiny hole in the flex hose, so the pressurized fuel would just spit back out into the tank.
You've already done the hard work of getting the pump out of the bike, so may as well do it right.
You should look into replacing the pump motor itself as well. There are threads here about how to check pump function outside of the bike, but they seem like a lot of work for a relatively cheap part.