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Bill
The gear up cycle is---
1 Gear handle to the up position which takes the power off the door solenoid and the doors open.
2 HYD pressure is supplied to the downlocks and unlocks the gear and the gear downlock switches open (very important)
3 Gear swings and HYD pressure is supplied to the gear jacks and the gear is lifted into the bays.
4 Gear lifts into the bays and passed the uplocks and pressure takes the gear up to ensure it goes passed the uplocks, the uplock switches should be closed to put on the amber light and pressure should put the handle back to center which takes the HYD pressure off the gear and the it hangs on the uplocks and power off the door soleniod which closes the doors.
Weather you put the gear up or down, power has to be removed from the door solenoid to close the doors, so any open circuit in the uplock circuit will cause the doors to open after retraction, it will also happen with the gear down as any open circuit will cause the doors to open as power is removed from the door solenoid.
As for the handle going to center, if is works in flight on a down cycle but not on the up cycle the time delay valve and priority valve must be ok.
Maybe this power pack being OHC has a better flow through it and the valves operate a little bit better than your old unit, the better flow may mean a higher pressure at the gear actuators which raises the gear a bit faster into the uplocks causing the switch problem.
But I do think you should replace these switches as they will cause you the same problem later on.
Just my views.
Regards
Pete
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