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I am not totally familiar with your exact camper however dumping the gray water tank has not changed that much over the years, well that I know of.
But, a prior owner may have changed something when they removed the black tank.
Normally there is a blade type of dump valve with a rod and a handle you pull to open the blade valve and the water comes out the dump pipe.
If you look in this pic, there are 2 handles in the black pipe that then connects to the brown dump hose. One handle for the gray tank, the other for the black tank. When you pull that handle, the water comes out
The valve body itself looks like this, just it should have pipe fittings on both ends. This is just a replacement valve
Does your camper have anything that looks like this?
If not, post a few pics of the dump piping outlet from the tank to the drain and maybe we can figure out what the prior owner did.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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