|
By the way, how much did a "new" hyd pack cost?
ANSWER: $1500 plus $1000 core
Thanks for the clarification re the pressure, obviously me (and my mechanic!!) are not reading the manual carefully enough. But to save me some reading (manual is up at the shop anyway, so I can't reference it at this moment) and perhaps lots of mis-interpretation which I am prone to..a few more questions if you can be patient with me:
What tells the priority valve to move, and assuming it moves and does something other than load the mains while the handle is still up (ie pump is loaded) where does the pressure go? Does it just come off the mains and reside in the pack waiting until the door solenoid activates the door hydraulics? I believe the only electrical action going on with the pack (on these early models) is the door solenoid.
It seems to me all this stuff happens pretty quickly, so doors open, locks open, gear move up, switches make momentary contact, but then due to the rigging issue already noted move past and re-open (with the light coming on for this split second, this actuates the door solenoid allowing pressure into the door hydraulic circuit), with pressure, the doors close but as soon as they hit the airframe, a bit of pressure builds and slides the door valve to the other side saying "open" because of the solenoid dropped out when the switch was lost, therefore doors immediately reopen. Handle never moves to neutral because this is a function of steady pressure build up with closed doors, and the time delay valve, which we are never getting to in this sequence of events.
If the above description is mostly right, it explains most if not all of what has been observed in flight, with the exception of perhaps a few things or a few remaining questions:
If the main gear are not remaining loaded (ie just residual pressure on the system) why is it when the handle is manually moved to neutral (during an in-flight test) do I get a steady light, but not when the handle is in the up position? NOTE: with the mule or the hand pump on the ground, we do get steady up light (with handle up) once mains go into the locks. So one additionaly theory is that the engine driven pump is putting out more pressure than the mule or the hand pump, forcing mains up a bit further and we thus loose the switch. But this theory only holds if the pressure is somehow remaining on the mains, or perhaps it is just higher residual pressure? But again if it is just higher residual, why in flight do we get a light when the handle is returned to neutral.
The reason for our original confusion and question was to determine if we have some kind of fault in the pack internal hydraulics (which remember is only happening in flight with engine driven pump doing the work) or whether we can isolate the problem to switches and electrical.
Thanks very much for your patience and help with this persistent, frustrating, (and by now quite expensive) problem.
Bill
|