440 ICD fuel lines

[Mark Birdeau]

When I took the hood off I noticed there are 2 lines that come out of the top of the fuel tank. One goes down the right side to the right side of the head. The other goes from the top center to the right side then across the front and is broken off there. I see no other sign of were it went. Is it needed and were would it go? It has always run good so I bet it has been gone since I've had the crawler. Mark:

[RANDY Fay]

The line out over the front is a vent have fun Randy

[JD440ICD2006]

The Detroit Diesel 2-53 has a high volume fuel pump. It sends up more fuel than the engine would need in most cases. This does several things. It insures that no air is in the fuel, it helps cool the injectors, and it warms the fuel over time.
Since so much fuel is returning to the tank most of the time, it must have a good vent so that pressure does not build in the tank

[carolina crawler]

DIESEL POWER RULES.........

[Mark Birdeau]

Thanks for the info. Thought that might be it. Wouldn't it run down to the bottom of the engine though, and not end right above the rear of the engine? Mark:

[JD440ICD2006]

From memory, it runs across the top of the tank towards the front of the tank and the rear of the engine. Then it turns 90 degees straight down for about 6 inches or so. Don't hold me to how long it goes, but it is not far.

[Mark Birdeau]

Thanks JD440ICD2006. Mark:

[thomastractorsvc]

On mine I am cheap so I ran my replacement rubber vent hose down the right side of the tank then zip tied the end to a point just behind the air breather so it cant get dirt in it. My return to tank line is also rubber pressure fuel hose with fittings. OEM is steel lines.