I was looking for a gas leak due to gas smell in the car the other day and I remove the panels under the cargo floor of the wagon. Both side Sending/Pump Covers were as rusted as can be. There was no leak, but I did the Krol/PB Blaster Treatment.

 

I hope I never have to pull them, I doubt the nuts will come off without the studs breaking. This was a MI car.

 

If I was in the Rust Belt, I'd pull the covers and clean and treat them.

I've had to overlay them with JB weld because they rusted through on my mom's 98 outback. Still leaks a bit, but there's no way I can replace them without snapping all the studs off. I'm not sure I really want to be drilling new holes into the tank either.