Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches February 27, 2026 ...

I bought my coach used so I don't know what was original on it.  It did have a black water rinse but on the street side which is only good to wash out the main drain valve.  Because I had "stuff" hanging up on the sensors (that are on the curb side) and causing false triggering, I added a second rinse line above the sensor probes on the top of the tank.  Both rinse units use a standard RV "city water fill" with a built-in check valve Amazon.com: Valterra A01-0172LFVP 2-3/4" Aluminum Finish Lead-Free Metal Water
The biggest concern with using a rinse line is making sure the flow doesn't reverse and contaminate your fresh water!
There several protections in the system I installed:
1.  City Water Fill fitting has a check valve built-in
2.  Garden hose "Y" splitter has manual valves.
3.  I have a short garden hose attached to the utility bay spigot.  I only attach this to the rinse connection when I'm actually doing a rinse and monitoring what is going on.  Ideally it would be good to have a back flow preventer on the utility bay spigot; code for most residential outside spigots.  I had one on it but it would sometimes release and spray water inside the utility bay - bad for bulkheads.  So I opted to take it out and vow to always be present when using the rinse.

To install the rinse that is above the sensors I had to use a hole saw on top of the tank and turn it with a wrench (no space for a drillmotor) - slow going but it's only plastic.  I think I also attached a string to the hole saw to make sure I didn't drop it in.  I sealed it with 3M 5200 and used stainless screws in the flange of the City Water Fill.  Then it was just a matter of cobbling together fittings with a hose that passes back over the top of the tank to where the garden hose "Y" is. 

There is another important detail (and I wish I could remember exactly how I did it - it been many years now) but I threaded something to the City Water Fill (on the side that goes inside the tank) to direct the water against the wall with the sensors.  It may have been just a 45 degree street elbow but I remember testing the spray pattern before installing it. 
It does do the trick.  I rarely have false readings and almost always use the sensor flush when dumping.