Car: Audi 80 tdi avant 1Z B4

Since changing the fuel filter a couple of days ago I seem to have residual air or a leak that makes first starting difficult. Need to turn her over for up to 20 seconds to get her to start. After that more or less ok, but I did stall once shortly after morning start yesterday.

*** Is there any procedure thats recommended to get rid of air in the system ? ***

I suspect though I may have air getting in, possibly due to lack of tightness in the hoses or elsewhere. No fuel leaks though.

She has always been an instant starter in the past, and I seem to remember always seeing *some* amount of air bubbles in the supply line to the fuel pump. There is quite alot of air there now.

I discovered there was a crack in the flange that the filter attachs to, where the return pipe valve fits to the top. This had been repaired by someone with some resin. I have had the car since new, so its been done by some mechanic sometime I guess.

Perhaps the solution is to get all the pipes and links from filter to fuel pump and the filter flange replaced.

Thanks for any help!

Timk