OK. There's your leak.
Here's your water ballon.
Begin plugging.
The tires would have to be inflated to a pressure great enough to create enough friction to enable them to grip a pipe that is slick with oil.
It was mentioned that you would not inflate with air, but with a liquid.
It would have to be a liquid that would not freeze at the temps encountered.
OK. There's your leak.
Here's your water ballon.
Begin plugging.