Not sure if your Sandpiper has the "docking station" on the driver's side where all the connections for water sewer are, but if it does, your pump is right behind that, you can access it from the other side, there is probably 4 screws and a panel comes off. The pump will be right there. I hope this helps.
Loving our Sierra 365SAQ
Nights camped so far in 2016 = 0
Although Many trips scheduled.