Air in my shocks - what am I doing wrong

[Loheswaran]

I am wondering whether or not I have lost my building skills and become a complete idiot.

I use a shock pump when building my shocks.

I then use the grub screw at the shock cap end to let oil blead out to set my rebound.

Once set - when extended the shock retracts - giving a type of negative rebound.

so I undo the grub screw in the cap - extend the shock - fine.

the problem is that they now make the familiar noise of their now being air in the shock.

I never had this problem with bladdered shocks - what's going wrong?