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v2k1966's avatar
v2k1966
Explorer
Jul 06, 2013

gray water tank

Our gray water tank seems to be clogged up. The galley part had water coming up through the kitchen sink drain. We just figured the tank was full so when we drained the tanks the water was still in the kitchen sinks.

The camper is a Couger 318 sab and only has the one grey water tank lever to pull. The grey water tank indicator says it is 2/3 full yet and we had water in the kitchen sink. We put in liquid plumber and that didn't work. We took the traps off below the sink and got a lot of water out that way.

It seems the plumbing somewhere below the sink is plugged. Can we run a plumbers snake through the pipes?

Has anyone else had any problems like this.

13 Replies

  • I have a Montana Mountaineer which is very similar to the Cougar.
    If you have a galley tank then the drain valve is not with the black and gray tank valves. My galley valve is under the camper near the sewer hose connection.
  • When you opened the grey water drain valve did water flow or just trickle out?

    Are you sure you do not have another grey drain valve.....back behind wheels/under slide??

    If water flowed then sink drain line could be plugged up.
    If water only trickled out then tank outlet drain hole could be plugged. Sometimes the cut-out disc (from installing drain/vent lines) falls into tank and is not removed......floats around until it finally gets sucked down to outlet drain opening and blocks the drain.

    Get a clear adapter that goes on end of drain line and then sewer drain hose connects to adapter.
    With the clear adapter you can see how well everything is flowing when draining.

    Tanks & drain lines are just like plumbing in S&B house......ABS. So you can snake the drain lines, use drain cleaners etc.
    BUT if you use any drain cleaners drain & flush lines/tank immediately after use. Drain cleaners can be harmful to the drain valve seals.