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You say the nose gear works fine so obviously the
gas spring is doing its job.
As far as the mains are concerned there are two
possible causes
!. Is the hydraulic pressure
going to zero to allow the gear to fall freely and get into a position where the
over centre spring can do its job? As I see it the spring is there to
push/lock the "knee joint " over centre and ensure the gear stays in the
down position. It is not there to bring the gear into the down
position. As a test for zero pressure you might just crack open the
connections to the cylinder one by one to see if the gear falls correctly.
If you have significant leakage from the opened connection and the gear falls
then I would think you have some retained pressure. More scientifically
you could TEE in a pressure gauge, in a convenient place,obtainable from Vern
quite cheaply and this will tell you exactly what is going on. You might
leave the T in place and cap it for future tests. Our hydraulic pumps do
strange things if the spool valve is not fitted correctly. See the
archives, there is a lot of good stuff there.
2. Is the strut and linkage free
of all binding? As I remember when I built my A/C the amount of space
available for the various components is very small and the linkage is free to
move enough to foul in some positions. The big rod end tends to move as
the gear moves. Also is the knee joint overtightened at the fork and blade
position? Check that the out board door linkage to the strut is free at
all strut positions.
3. As I remember the rat trap
springs were changed at one time. There had been a problem with their
manufacture and some broke. I believe the design was changed and the heat treat
more closely specified. However Vern would know.
Good Luck
Ian Crowe
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