Water Tank Drain Question

[TexGX]

I took some time this weekend to clean the water system in my new to me van. I added bleach to the tank and wanted to drain and fill a few times to sterilize everything. When I opened the drain for the water tank, it leaked out from under a metal plate under the truck. The drain for the water heater comes out behind the rear drivers wheel.

Where does the tank drain and overflow come out?

I ended up just opening the grey tank and using the pump to empty the tank a few times to get the system clean. I ran the bleach water (hot and cold) though the sink and shower then flushed with clean water. It should be ready to go, but would like to know how to get more water out of the tank without needing the pump.

Its a RB50 floor plan with tank under seat.

TexGX

[BogusBlake]

Both my overflow and main drain come out somewhere under some plate under the van.

There's actually a bunch of drain cocks that all empty somewhere different- main tank, heat exchanger, city water fitting, aft shower... I just open 'em all up. When it's just a trickle, I drive around for a while to make sure anything that could slosh would find it's way out.