Another thought, not knowing the location or the severity of the crack. You might want to take a look at J-B Weld. It is an epoxy resin with hardener that I have used many times for cracks, bonding and leaks, even those under significant pressure. Once hardened, it is hard as steel and is impervious to water and most other fluids. Like most of these products, surface prep is absolutely critical to ensure a lasting fix. After it hardens, I would put the Eternabond over the area....as added insurance. If you have interest, send me a PM, and we can discuss it further. The stuff is available at auto parts stores and other retailers....and is not expensive at all.
Best of all, it works! Just a thought....
2003 Fleetwood Revolution DP