In replacing my fuel pump, I found that my fuel pump was missing its float and had a disabled sender, evidently not the original fuel pump. I want to replace the check valve(s). Both my feed and return elbows have check valves. I assume this is for the roller pump type fuel pump with a separate supply pump that may have been original equipment in my Saab. But most of the check valves and kits I see for sale online only have the feed elbow with the check valve and a straight through elbow for the return. Since the current fuel pump is a rotor type, minus the float, is a check valve on the return elbow necessary?