Diesel Fuel leak

[Chris]

I have noticed a very small amount of diesel fuel in the engine valley.
I can also smell it outside the front of the bus after a drive. I have
looked all over and only found a one loose bolt on the pump. It was a
bolt on the side that faces the valley or back of the engine. I
tightend it and I still have fuel in the valley. I have checked all
around and can't locate any leaks.
Should I be real concerned with this leak? It's not much....
Engine still runs fine...would it be taking a big chance to go one a
longer trip with this leak?
Thanks
Chris Reed
83 FC35 SB
Plant City, FL.