Ford 1720 injector question?

[Bedlam]

Probably a simple question but I have a system like the picture.My question is what are the small "low pressure' line for ?they run between all the injectors and the last one goes to the fuel tank. Is it some sort of vent or is it a return line for fuel?The one on my far left that goes to the fuel tank might be leaking slightly. I can wiggle the clamp quite easily. and what a small clamp ...much smaller than I'm used to.
Thanks for anyone help with this..

 

[HakanTh]

It is the return line, or leak off line. The injector is explained here:
Working of Diesel fuel Injector and how nozzle spray - YouTube

 

[JC-jetro]

it is the return line/over pressure line that returns unused portion of fuel back to the tank. The flow is very little on my 1700 and pressure is even less. I just overhauled and then replaced my steering column and anytime I take that lil hose off the tank I might have drop or two of diesel and not much beyond that.

JC,

 

[Bedlam]

Thanks.ill watch that video. I assumed it was what JC explained. its an old hose as I have never replaced it.I took it off and found the end of it to be pretty ''mushy' so cut the end off and then squeezed the clamp tighter. I sort of remembering doing the same repair years ago. As the hose is getting shorter LOL next time ill have to replace it from the tank on down to the injector. Thanks for the info

 

[thepumpguysc]

U have to be careful w/ some Ford return lines.. On some mdls the INJECTOR return will actually be routed back to the filter head..
& if u get a cracked line, it will pull air into the filter head.. & you'll be chasing air in the fuel problems till your hair falls out..
BUT it sounds as if u have a good handle on your flow back to the tank..
The return lines are for just as described.. {for the most part}

 

[Bedlam]

U have to be careful w/ some Ford return lines.. On some mdls the INJECTOR return will actually be routed back to the filter head..
& if u get a cracked line, it will pull air into the filter head.. & you'll be chasing air in the fuel problems till your hair falls out..
BUT it sounds as if u have a good handle on your flow back to the tank..
The return lines are for just as described.. {for the most part}

hmm interesting , there is another hose thats the same size that comes from the tank to the filter head.