Gate/Dump Valve suggestions..

[azflycaster]

Possible paper blockage. Shoot water back up to the tank and wait for the surprise.

[Bill M.]

Do you leave the black water dump valve open and stay hooked up? If so, that is your problem. Or are you hooked up with a leaky dump valve? Anyway you need to keep a lot of fluid in the tank and dump half full or more loads. When we live in our parked trailer we keep the waste valve closed and dump every 5 days or so. Has worked for a long time.

Glad it is not the valve. Maybe fill the tank half full of liquid and take the trailer for a ride on a bumpy road? Maybe use a pressure washer from the outside?

[Mollysdad]

Originally Posted by groundhogy

I think not enough flush water was going in which started the pyramid building.

Never leave the black tank drain open while camping. It allows the water to drain and builds the dreaded poop pyramid.