Fuel Pre-Filter Plastic Line
 

I just replaced all plastic fuel delivery and return lines (including the fuel pre-filter seal & fuel filter). However after 10-15 cranks there is only air and no fuel in the plastic delivery line which comes to the pre-filter. All other lines (five of them - six in total) show that they have fuel.
How many other cranks should I try before the air is removed by the pump? I am concerned that I may have done something improper.

It is a '99 e300td with 115k
 

It is a '99 e300td with 115k

Your IP needs to prime the system.

To do so you must crank the starter for 30-40 seconds. If a repeat is needed it is recommended to wait a few minutes so as not to overheat the starter motor.

It may take to or three tries.

When you think it has caught, keep cranking a few seconds longer to be absolutley certain. Not being certain results in 2nd and 3rd attempts and eventually the battery wears down.

Will usually run rough for a second or two and then even out as the IP gets rid of the remaining air in the system.

Should be fine after that.

Thnaks for the advice. It worked perfectly (tried 2 more times).
I already driven the car 100 + miles but there is still air visible in the plastic fuel line which leaves the pre-filter. Should I be concerned?

Any fuel leaks anywhere? Where fuel leaks out, air can enter.

Most folks dont replace the line from the inside of the IP (has a banjo bolt, black fuel hose with clear line intersecting), it has o rings where it enters the fuel filter housing that should also be replaced. My dealer parts person said no one had ever ordered that part so I only replaced the o ring on mine.

I had a frothy stream of bubbles at certain RPMs after replacing my lines and difficulty starting and loss of power at times. I had to replace the fuel shut off solenoid (black plastic valve with 3 lines and electrical connection) mounted on the side of the IP.

As I udnerstand, the shut off solenoid should turn on the check engine light if malfunctioning although it may not if only leaking.