Crack in Black Tank ABS Elbow

[cdspark]

I am prepping for a trip next month and in the process of crawling around underneath I bumped the clean out for the holding tanks. Later I noticed a wet spot on the ground and found a crack in elbow from the black tank to the shut off valve. There are actually 2 cracks, one in the collar and one in the elbow itself. I have attached a couple pics. The one in collar is right near the top, the other is in the bend.
Any suggestions on a temp repair? Will the Duck wrap fix hold it? How much trouble is it to replace the elbow.
Thanks for any help.

[Thomas ho]

go to a r.v. supply ,buy a can of black tank repair .buy a square of fiberglass cloth . cut a strip to cover crack. paint on glue ,then cloth , press st saturate. coat again , not real thick , then repeat horizontal strip, repeat. it works

[cdspark]

Thank you for your response. I made the mistake of presenting the idea to the DW. She immediately said "You get it replaced, I don't want to be out and all of sudden the black empties." So now I am ordering all the replacement parts to rebuild that section completely.
The tank hub, street 90, and Bristol flange all came out together without too much struggle. Since its all glued together, its rebuild another set and re-install.
Any suggestions on the butyl sealant for the hub going into the black tank? I was able to loosen the hose clamp holding it in, and then gently twisted and pulled on the hub and the sealant was flexible enough to give way.
Thanks again.