We have been having a problem with the black tank leaking when it's almost full and sewer smells when driving. The black tank seems to be original so I decided to replace it. This was the longest and worse project I have done yet, mostly because I made a few mistakes along the way. I hope if you ever have to do this project it goes better for you.

Here are some of the key parts and tools I used.

Black tank:
https://www.gmcrvparts.com/product-p/...

Blade valve:
https://www.gmcrvparts.com/product-p/...

Level sensor:
https://www.gmcrvparts.com/product-p/...

Toilet seal:
https://amzn.to/3vwQe12

Hole saw (1 1/2"):
https://amzn.to/43AcGDk

Hole saw (2 3/4"):
https://amzn.to/4cxiIsu

Hole saw (2 1/2")
https://amzn.to/43yICYC

Expanding foam:
https://amzn.to/3TyVvNO