My problem is that hydraulic fluid is leaking from the
low side to the high side of the cylinder operating
the nose gear.  There are no leaks or at least no
visible hydraulic fluid leakage.

Initially I removed and disassembled the hydraulic
cylinder and discovered that it was scored.  I
replaced it with a new one but within 6 hours it was
also leaking.  I have disassembled this second
cylinder and it was not scored.  I then replaced the
O-rings with no success.

The pressure sensor on the pump was set at 750 psi
when new, and I have lowered it to 600 psi.  It leaks
down to 300 psi then the pump cycles on to kick it
back up to 600 psi.  The Gage moves quickly from 600
down to 450 then begins to slow until it reaches 300. It holds 200 psi overnight.

I believe that when the cylinder is fully extended
there is a bending action going on possibly because of
the geometry between the motor mount and the location
it attaches on the gear.  While I cannot see any
bending taking place in the cylinder, I do see the
motor mount moving slightly.  I suspect this movement
allows the bracket where it attaches to move just
enough to cause the bending in the hydraulic cylinder.

Does anyone have any thoughts on this?  Is it possibly
the hydraulic pump that is not functioning correctly? If it is the motor mount bending, are there
suggestions on how to fix this problem?  What is the
minimum pressure I should set on the pump for the low
pressure side?

Thank you in advance for any advise.

Art Jensen
LEG2 927J



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