If I was you guys I would call the chassis builder. You either have the Spartan or Freightlliner, most likely it is a Spartan and ask them where the second fuel filter is. Most have one on top of the engine with a pump attachment in case you have to prime the system. And then it would probably also have a filter water separator on the extreme rear of the coach right outside the radiator. Like I posted before, mine only has one on the rear, outside the radiator. It is very easy to change out.
