Cougar 326 rds galley gray water tank

[BamaTurner]

My galley sink would not empty it was like it was clogged. I plunged it and I snaked it and could not get it to work after much research I found that there is a separate valve away from the two main gray and black water valves to empty the tank it is in the left hand wheel well behind your dinette slide out you'll never find it if the slide out is in here is a picture.

[wiredgeorge]

Same place as on my camper. I have to crawl under my slide to open the valve behind the rear wheel on driver's side. I have a gate valve on the main sewer outlet and leave this galley tank valve open when camping. Not fond of crawling under the slide to open to dump the galley tank. Use the gate valve to dump it.

[Prawnstar]

It just cost me two bucks to find out I had two grey tanks. Had the same issue as the OP