dirtfun, welcome to iRV2.com. Sorry to hear of the water leaking issue. Water can travel even up hill (called wicking) so don't give up looking for it. You might want to use a little higher pressure ( up to about 60 psi) from an outside source. This will cover everything from the discharge side of the pump. If you do not find it, then the leak is on the suction side of the pump, the fresh tank or the plumbing in between them. Good luck and keep us posted.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7