First off, Welcome!
Your holding tank can be repaired. The cost is not that high to repair it, but it will take some time. The tank is made from ABS plastic that can be solvent welded/cemented to seal the pieces back together. There are also resin kits to patch very large holes.
Many club members have done this before. This link will take you a recent post talking about ABS plastic repair and repairing a tank. There are links off this post to more detial. https://www.sunlineclub.com/forums/f...tml#post151851
If you scroll down some more, to post # 12 & 14, there is also a post by jim44646 that talks about the resin kit with pics.
The tank in this pic of yours, and if this is the cracked tank, appears to be the gray water tank which collects the sink and shower drain water. The smaller 1 1/2" discharge pipe is on the gray. The black tank for the toilet has a 3" drain port.
This picture shows what looks like flashing around the toilet drain pipe.
This may be a separate issue, I cannot tell without more pics of the other end of that larger drain pipe. It appears that something may have yanked hard on that pipe and pulled the flashing loose from the bottom of the camper. By the looks of the dirt marks on the bottom of the camper, this flashing separation has been on going a long time. It may have been done long before you bought the camper.
Check the fit of the pipe fitting to the toilet that it is tight and check the other end of the piping after that elbow. There may or may not be damage to it. Can't tell from this one pic. After you confirm the pipe and toilet connection is OK, then try and straighten out the flashing and reattach it to the bottom of the camper.
Let us know if you need more help.
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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