Bonneville gas leakage problem
 

I have a 97 Bonneville SE and it is leaking gas recently, I sent it to repair shop and was told that the sending unit got problems. they asked for $300 for replacement. I have no idea abou the price for this replacement and wonder if $300 is too expensive for such a replacement?
many thanks in advance.

just an FYI.....the sending unit will not cause gas to leak as its located on the top of the gas tank...and makes a seal with the tank

The point is that when the car is not running it is fine. it leaks gas only when it is running. also, this car's gas gauge does not work, it always points to the full position. so I think the sending unit may be problematic and wonder if $300 is reasonable for the repair shop to replace it.

can you see where it is leaking?

the gas is flowing along two wires from gas tank, that's all I can see.

Locked for double post.

Please refer to 92-99. And please don't post mechanical issues in General Chat.