My main gear actuators were leaking so I overhauled them.  This isn’t a big deal and I’ve done this numerous times on spam cans with no problems.  Upon reinstallation I found two situations; the left main wouldn’t respond at all; the inboard and nose wheel doors wouldn’t stay closed.  Since this is a closed system and I could see signs of leakage on at least one gear door actuator, I figured before messing with the gear I better rebuild the gear door actuators too.  I did that, reassembled everything, and ran leak checks after cleaning the previous leak mess.  Now, this situation remains…sort of.

After several gear cycles, the left main wouldn’t break the over center down lock.  I decided to tap it with a rubber mallet to break it loose just to see what happens.  At that point the pump kicks on and the wheel goes up but the doors still bleed down and open after less than a minute.  I now have probably a dozen or so gear cycles and, although the left main is now responding, it’s the last to do so but only after what must be called a burp in the system.  By that, I mean the other two legs go up, the pump stops momentarily and then kicks back on to take the last leg up.  But, the doors still bleed down and come open in less than a minute.  I can't see any visible leaks so this tells me there must be an internal leak someplace.  The question is where?  Can the sequencing valves cause this or is it the emergency extension ball valve or something else?  And how do you check these items for internal leakage?  Any suggestions would be appreciated.

Thanks in advance,

Danny

LNC2-360, 550 hours

N 38° 43' 25.7"

W 77° 30' 38.6"