Posted for "Gerard O Connell" <goconnell@dodo.com.au>:

 
 Thanks Dan, I thought that this (vibration) might be the problem and tried
various ways of tightening the fit (used rubber between the door and airframe
etc) but apparently ground observers say my door hangs completely open in
flight and sometimes I would hear a short cycle from the pump and the buzzing
would stop abruptly when it slammed shut. The current problem is that on
retracting the gear it doesn't close at all.
 
 I used to have the problem with back pressure in the down line..this
manifested as the nose gear door closing in 3 quick jerks as the pressure bled
off during retraction. I'm pretty certain the current problem commenced after
I replaced the valve assembly which solved problem number one (the jerky
closure). I wonder if the spool valve problem manifests itself in various
ways??? Do you have any other experience of this?
 
 
 --
 Gerard O Connell
 Melbourne, Australia
 VH-LPD (LNC2)