Im in a 99 rexhall rexair, i went to drain the tanks like normal, apparantly i left the valves open last time, after i used the flush system for 5 minutes i opened the valve. i had mainly fluids come out than it clogged, tried to fill it up to push it out (which had worked previously) now im stuck with an almost full tank and a clog. A tiny amount of fluid seems to build up past the clog when you leave it alone for awhile. After research im fearing a pyramid. I even tried filling up the sewer line with water and lifting it above the tank to back flush it, but it didnt work. Also tried taking it for a short drive. My wife dumped a gallon of bleach down the drain yesterday. In a week ill be taking it for a 4-5 hour drive. Best thing i got on my own is treat it with some ridx and drive it in a week and hope it dumps whe i get there. This however is not ideal obviousy. Calling a professional is a last resort and i dont need advice on how to do that :)

Are you sure tank drain valve is even opening :H

Yes im positive the valve is operational.

You may be able to siphon or pump most of the liquid out through the toilet. At least get enough out that when you drive it there is room for some sloshing around of contents. If that doesn't work you are going to need a really good friend to help you. One hold the slinky and the other on feed a snake up the drain line (if I was the friend you would be holding the slinky). Poke a hole through whatever is blocking the tank opening. Once it is open retract the snake and get the slinky hooked up. As the water flows it should open up a larger hole. After the tank is drained get back in there with the snake and work it through the opening of the tank several times to bust everything up. Fill and flush to get the rest cleaned out.

X-2 on using a snake or flexible rod to poke at the clog.Unfortunately could lead to a messy embarrassing moment if your not careful and ready for the break up.

Would it be possible to drive the RV onto boards so it's tilted away from the hose connection? Then you could get the blockage out of there, set the RV level and drain.

blocked black & grey water tanks | Good Sam Community

27 Replies

4X4Dodger
Explorer II
Mar 27, 2016
bobwalter wrote:
Glad it worked.... Now, use plenty of water and don't dump until your black tank is almost full. Do not leavi ti hooked to a sewer with the valve open. Keep it closed and only open it when tank is near full. Oh yea, did I say to USE LOTS OF WATER!!! Water makes for a good dump. Lack of water causes constipation;) That not good for you or for your RV.

X2 X2X2!
4X4Dodger
Explorer II
Mar 27, 2016
nomad.297 wrote:
Go on your roof and put a Drain King on the vent for your black tank. It will build up enough pressure to force the stoppage out of the drain. This won't work for your gray tank.

Edit: It will work for your gray tank if you know how to cap off your shower and sink drains. I'm a plumber, so I know I could do it.

Bruce

The kind of pressure needed here could very well split your tank. I would NOT do this. I have seen plastic waste tanks split with just hand pump pressure.
CWDoc115
Explorer
Mar 27, 2016
I had this problem a couple of months back, & once it was cleared up, I had a tornado tank rinser installed in my 99 Adventurer.
nomad_297
Explorer
Mar 26, 2016
Old-Biscuit wrote:
nomad.297 wrote:
Go on your roof and put a Drain King on the vent for your black tank. It will build up enough pressure to force the stoppage out of the drain. This won't work for your gray tank.

Edit: It will work for your gray tank if you know how to cap off your shower and sink drains. I'm a plumber, so I know I could do it.

Bruce

Good way to blow the grommet out that some mfgs use to seal toilet drain line and vent line into top of waste tank. Might work OK if those lines going into top of tank are glued but those that use grommets are just friction seal. (same with grey tanks)

Could get real messy plus labor intensive to reinstall drain/vent lines back into top of tanks

It would push a stoppage through way before there would be enough pressure to pop the grommet out.

Bruce
Old-Biscuit
Explorer III
Mar 26, 2016
nomad.297 wrote:
Go on your roof and put a Drain King on the vent for your black tank. It will build up enough pressure to force the stoppage out of the drain. This won't work for your gray tank.

Edit: It will work for your gray tank if you know how to cap off your shower and sink drains. I'm a plumber, so I know I could do it.

Bruce

Good way to blow the grommet out that some mfgs use to seal toilet drain line and vent line into top of waste tank. Might work OK if those lines going into top of tank are glued but those that use grommets are just friction seal. (same with grey tanks)

Could get real messy plus labor intensive to reinstall drain/vent lines back into top of tanks
tylerhomesteadm
Explorer
Mar 24, 2016
Wont make that mistake again, much thanks my friend.
bobwalter
Explorer
Mar 23, 2016
Glad it worked.... Now, use plenty of water and don't dump until your black tank is almost full. Do not leavi ti hooked to a sewer with the valve open. Keep it closed and only open it when tank is near full. Oh yea, did I say to USE LOTS OF WATER!!! Water makes for a good dump. Lack of water causes constipation;) That not good for you or for your RV.
tylerhomesteadm
Explorer
Mar 23, 2016
bobwalter wrote:
Get the clear plastic elbow with the garden hose connection. Put a cap on the end, hook up the garden hose, open one sewer valve and turn on the garden hose. This should clear the clog. Close the valve and remove cap with a bucket underneath. attach sewer hose and dump...... Use garden hose as needed to break up any more clogs. Do both tanks the same way. GOOD LUCK!!!!!!!

This man is a genious!!!!! This worked beautifully and i didnt get poo'd on!!!!!
nomad_297
Explorer
Mar 23, 2016
Go on your roof and put a Drain King on the vent for your black tank. It will build up enough pressure to force the stoppage out of the drain. This won't work for your gray tank.

Edit: It will work for your gray tank if you know how to cap off your shower and sink drains. I'm a plumber, so I know I could do it.

Bruce
bobwalter
Explorer
Mar 23, 2016
Get the clear plastic elbow with the garden hose connection. Put a cap on the end, hook up the garden hose, open one sewer valve and turn on the garden hose. This should clear the clog. Close the valve and remove cap with a bucket underneath. attach sewer hose and dump...... Use garden hose as needed to break up any more clogs. Do both tanks the same way. GOOD LUCK!!!!!!!