Chris,
Thanks a ton for all the perfectly clear
response.
<<This
indicates we have a internal cylinder leak.>> I don't understand this
conclusion.??
I apparently concluded this in
error. I assumed the downside back pressure was caused by leak
through. I now know that the downside back pressure is always present and
may not indicate an internal leak.
Thanks again, we’ll take a
closer look.
Larry
From:
Christopher Zavatson [mailto:Christopher.Zavatson@baesystems.com]
Sent: Wednesday, September 13,
2006 9:16 AM
Subject: Re: [LML] LNC2 Hyd Spool
Valve Reverse Revisited
<<The gear
could not be raised by hand even with the dump valve open.>>This is
normal. The back pressure circuit does not open until the spool valve is
moved by the pump.
<<We
cracked a hyd fitting to relieve the pressure (which worked). >> There
is a cleaner way. After you open the dump valve, bump the hydraulic motor
in the up direction to let the spool valve open the back pressure
circuit. You can then raise the gear by hand.
<<This
indicates we have a internal cylinder leak.>> I don't understand this
conclusion.??
<<However,
is this only true in one direction?>> Yes.
<<That is,
when the gear are up, does it bleed the downside pressure?>> Yes
The "poor
man's" test for the reversed spool valve is to reverse direction while the
gear is on its way up.
Aren't these
hydraulics fun.