I've had issues in the past, my solution:
1. Remove syringe piston and lube rubber plunger part with mineral oil. Test it to make sure it slides up and down nicely as it does expand if used before.
2. Load syringe with oil and mount to calliper bleed port (once air has been squeezed out).
3. Open the bleed hole at least 1/2 a turn, you can go a bit further it won't hurt the system at all. You need to this part to make the oil flow. no idea why they star a 1/4 turn?
4. it will slide on up smooth as (obviously given that the lever has the funnel attached, little plunger removed, and lever is not pressed in or anything.
5. run a fair amount of oil through, tighten up nice and tight at the calliper bleed port and your done at that end.
BTW - if you then bleed down you can test what I'm saying about opening up the bleed post more than 1/4 - no oil will come down if it's to tight at this point. ease it open till is flows nicely - then you know how much to turn the threads in the future.