Black and grey tank not emptying completely

Are you seeing fluid in depth or possibly just a little on the bottom. Take a dowel and put down the toilet and see how much is really in it. Are you fairly level when dumping?

Good suggestion from Dennis12 above.

Also are you level or slightly leaning toward the out-flow pipe when you dump?

On the last dump of the trip I elevate the side without the valves by 2 inches using plastic levelers.

Lwiddis wrote:
On the last dump of the trip I elevate the side without the valves by 2 inches using plastic levelers.

I hope you're not in front of me doing that at a dump station. The amount of time you take doing that would just back up the line even more.

As level as possible. There is 2-3" of fluid in bottom of black tank. After I drive for the day and hook up again, it all drains. It's done this the last two times.

You could have debris built up between where you're seeing the fluid and the valve (small wall). Fill it about 25% full between campgrounds, add some detergent or chemical and drive to the next campground. You may have to do this a couple of times. You can also buy a toilet wand, or make one from pvc with a hole at the end on one side and spray thoroughly for a few minutes, directing the spray toward the valve.

deleted, dual post.

We Cant Wait wrote:

Lwiddis wrote:
On the last dump of the trip I elevate the side without the valves by 2 inches using plastic levelers.

I hope you're not in front of me doing that at a dump station. The amount of time you take doing that would just back up the line even more.

Nice comment, unless you are volunteering to do his dumping, he is making a big mess, then you should help them with some advice.
Yes, you should elevate the side away from the dump valves, and if the valves are to the back of the MH, try having the front higher than the back. it is dis-hearting to have 1/4 tank after dumping.

I would think the tanks would be designed to empty when the MH is level. In 7 years full-time, we have never seen anyone tilt their unit, no matter what brand it was.

It might be how you are managing the tanks in general. I got these tips from a full timing book. Never let the tanks go dry. You always want at least an inch or two of water and chemical in them, that way when your going down the road the back and forth movement creates a washing machine action and helps the chemical along. Try to have the black tank as full as possible before you dump it. It gives greater gravity action to help expel the waste. Lastly, I use only Thetford Aquachem with the blue cap. I've never found anything better and I been disappointed with the different powders and such. I have never had a problem in 20 years, just keep that tank wet.The fluid level should always be above the waste. If it's been a week or two add another bottle can help. It could be that you have sludge build up near the front of the tank.