This has been covered at great length before. Some
take the position that "real pilots" don't need anything but the dump
valve.
I have proposed two answers,
1) replace the dump valve that only opens a port
between the HI and LO sides with a dump valve
that dumps back to the pump reservoir.
2) install a small electric module I make across
the pressure switches that runs the pump to relieve the over pressure
in the "wrong" line automatically.
Wolfgang
----- Original Message -----
Sent: Saturday, January 26, 2013 2:07
AM
Subject: Re: [LML] Re: Thermal influence
on Hydraulic Pressure
This has happened to me even at the beginning of a flight, if the temps
in the hangar have gone from cold on a previous day, to warm on flight day.
I guess cold temps shrink the fluid and suck more from the reservoir
into the lines, and when it warms, the pressure builds on both sides of the
system, so that the "up" and "down" pressure switches are both open and the
gear won't move until I pop the bleed valve.
Nasty when the gear won't retract just after blasting off into a low
overcast.
Charley Brown
Legacy #299 200 hr
On Jan 25, 2013, at 7:23 AM, randy snarr wrote:
.
I dont like having to open the dump valve but it is necessary once in a while
especially when it is cold. The pressures on both sides of the system climb
due to the engine heat and the gear sometimes will not move without dumping
the pressure.