Ok here's the fix.
To make it easy to access the pump remove the back wall, it pops off easy. The culprit is the boom hose that breaks. The photos show how to repair the break. The hose coupler has to have a 1/8 ID to function correctly but not over 5/32 ID. The original Lionel hose will fit snugly into the coupler and provide a leak proof connection. The feed hose does not need to be repaired unless you want to do both. The fuel hos can be purchased at any hobby store that carries radio controlled cars or airplanes. Lionel is in the process of buying the correct hose. I'm sure they would send a piece upon request once they have it.
