Seneca III Landing Gear Hesitating to Lock Down in Flight

[ryz]

Seeking the wisdom of the internet collective for our current riddle. Here's the backstory:

• Plane purchased in November, ferried home in December. No issues with gear on ferry to pre-buy, after pre-buy test flight (some exhaust components repaired so we did a spin before heading out), or on the flight home.
• Plane goes in for annual in January, no issues.
• Gear swings during annual, no issues.
• Coming home from annual, takes 3 cycles to get 3 green. Emergency extension not attempted in flight.
• Put the plane back on jacks, it swings fine.

Our current theories:

• Wind load seems to be a factor, since it works on the ground.
• Could be a microswitch "sticking" or positioning issue.
• Could be a hydraulic issue:
  • Power Pack (HYC5005) rebuilt in 2015
  • Gear flexible hoses are from 1995 (yes, it's on my list to replace these on general principle)

One specific question: does anyone know (or have a photo) of what the vent screw is supposed to look like on the hydraulic pack? The MM seems to show a washer, but also mention to maintain 1/64" clearance to the small vent hole, which the washer covers...

Any additional thoughts or suggestions as to what to try are greatly appreciated. Right now our next step is to make sure the microswitches are correctly aligned, as that is relatively inexpensive compared to starting to poke at parts...

 

[ikaros61]

 

[philiplane]

 

[ryz]

 

[philiplane]

 

[ryz]

 

[kju1pitt]

 

[timmccall]

 

[EchoDelta]

 

[flyguydon]