Fuel flow

[mobenz]

I am trying to figure out the direction of flow on my 1978 300CD. There are two lines coming from the tank. At the main filter, there is an in and an out arrow, which makes sense. There is also a line coming off the top of that filter that connects to the "cigar" hose. Basically, I am trying to determine which line is bringing fuel into the injection pump. Any help would be greatly appreciated.

[sixto]

The hose connected to the bottom of the tank strainer (round thing with a 46mm hex formed into it) is the supply line.

The cigar hose goes back to the tank.

Sixto
87 300D

[sixto]

Oops, I misunderstood. The line running from the lift pump attached to the injection pump to the big filter is the supply line. The center fitting at the big filter goes back to the injection pump.

Sixto
87 300D