It is usually routed through the uni-body of the vehicle. Make sure the pump has enough power for the distance, and test the line at every join you have access to. If you figure out which section is bad, then you can disconnect the join, and attach a replacement length to it, make sure you have some extra length of the new just in case, and pull the new through with the old like fishing. Make sure it is joined securely as there are probably bends and exposed sharp edges inside the body channels. Don't pull too hard, and have someone feeding it through from the other end jiggling the line and such.
