Fuel smell and leak under severe load.

[Brawnyrebel]

My dad just called me from the road and said he smells fuel and had a small amount leak off the bell housing of his 03 f250. He was climbing a steep grade with a bed load of wood and hauling a 28 ft travel trailor and had to stop. When he took off he was getting at it pretty hard to get the load moving again and the smell started and when he stopped he noticed an oil rainbow below his tranny. The truck only has 36,000 miles on it and is well maintained. Does anyone know what that may be and if it is a big deal? I was thinking ccv? I appreciate any advice

[Bushwakd]

Check the Fuel bowl drain valve. The o rings tend leak after several years. New ones can be found at Diesel o Rings.com
As it leaks it could get in the top engine valley and pulling a steep grade it leaks out the back of the engine valley through a drain hole.

[Brawnyrebel]

Thanks. I'm going to call him later and pass on any info before he heads back.