Replaced a front steel line. Can't get much of a brake pedal. Should I be bleeding them with the motor running because of the booster? 1994 E 150 302
I have never seen a Ford that was done that way, but I know some Chevy's are.

 

Will check if your vehicle has split brake system ,,,,,,,,,,LF/RR & RF/LR. If so air may have managed to get into lines for one side of the rear wheels. Best if possible to bleed all wheels.

 

No, you do not need to have engine running.However, I would not be pushing the pedal all the way down to the floor to prevent damage to the master cylinder. If your van has four wheel ABS, you may need to use the appropriate scan tool which will activate the ABS solenoids when you bleed to get all the air out. How exactly are you bleeding?