If yours are still in good shape they might still seal, otherwise you can just use the green HNBR o-rings like they use for A/C systems. At first that is what I did but then the pressure hose from the pump started leaking at the first joint betweeen the hardline and flex line, so I ended up having to replace the whole thing anyway,
If you take the old o-rings to someplace like NAPA they can help you find new ones that are the same size. I can't recall exactly what size the ones I used were but I think I still have them on the old hose, I can check later. The white plastic one on the high pressure line can be left alone unless you somehow damaged it. If it is damaged, I don't think it's really possible to get a replacement, you'll just need to get a whole new hose set. Which depending on how many miles are on your rig, you may want to do anyway. Like I said, I ended up having to replace mine anyway, they had about 180k miles on them I think. I picked up mine from RockAuto.com, They aren't cheap at around $80, but they're not super expensive either and compared to losing a hose while driving it's cheap insurance.
