Cracked flare fitting

[MarkT]

I just wanted to post a tip concerning fuel lines. I have a 1999 3000 Express powered by two Cummins 4 BTA diesels. They have been running very well but this past September as I was backing into my slip the port engine almost died on me. I let it idle as I tied up and it started running very rough. I had my wife shut it down and I came back the next day to work on it. I figured it was time to change the fuel filters so I did that along with the oil change. After I primed it both engines started right up. But within minutes the port wavered and then died. I figured it was just the prime so I did it again and she started right up only to die again. I primed it one more time but when I started it I saw air coming into the bottom of the Racors. I knew I had an air leak in the supply line but where? Since I had no diesel in the bilge I figured it was high in the system. On a hunch I took off the fuel line at the tank end and found the flare fitting had cracked and was allowing air into the system and losing prime. I took the fuel line out and was able to get a new end crimped on saving me the cost of a new line.
If you ever have a bad running engine don't forget to take a look and see if you have air coming into the fuel filters!

[USA591]

Hey Mark T,

When you say you "saw air in the Racors", does that mean you have the clear plastic bowls? If so, are your filter separators in the engine compartment? The manual says that's a no-no, but I'm not so sure it really matters--if it gets hot enough in there for plastic to melt (and create a fire hazard), it's not gonna be just the clear bowls that melt...right?

[MarkT]

They are Racors with a clear bowl. These are diesel engines and the filters are made for this application.