Air, Worn, or Stuck: HLAs on EJ22?

[HobbyWrench]

I'm doing a HG replacement on a '90 EJ22 (175K miles) and have pulled the valve rockers to replace the valve seals.

 

Inspecting the hydraulic valve adjusters in the rocker arms (just on the left head so far), I've noticed a couple (#2 cylinder: rear exhaust, rear intake), which can be pressed down slightly (probabaly about 0.5mm) and then stop (slight click). There are 3-4 other HLAs that appear to be shorter than the others - they do not move when tested with the 'finger squeeze test.'

 

Do the ones with movement just need to bled of air? How does air get into these?

 

Are the shorter ones worn? Or they possibly stuck part way in?

 

Would it help to remove these and soak/fill and bleed them in Seafoam, followed by fill and bleed with/in oil?

 

Thanks!