Keith,
You should never have to resort to wrenches to get the wheels up –and that is not just speaking from a safety perspective.
The following is an extract and renumbered set of slides from a LOBO maintenance seminar on the 320/360 hydraulic system. Slide 21 shows one possible explanation for your system’s failure to retract.
http://www.n91cz.com/misc/LancairHydraulics-LML.pdf
Temperature changes will cause pressure to go up and down, but should only affect the currently operating side of the system. The non-operating side should be zero and remain zero unless there is some other failure or configuration issue. If both operating and non-operating sides are affected by temperature – investigate.
Note that earlier vintage pumps (~235 era) were internally different.
You may also find some of the following of interest:
http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm
Chris Zavatson
N91CZ
360std
www.N91CZ.net
From: Keith Smith <keith.smith@gmail.com>
To: lml@lancaironline.net
Sent: Thu, March 31, 2011 12:24:59 PM
Subject: [LML] Re: LNC2 Gear Hydraulics
Quite possibly one of the best posts I've ever read. Thanks, Tom, for taking the time so share those experiences!
I recently experienced the inability to raise the gear. A quick call to Rick Argente (Lancair owner/builder in NJ) provided the solution...bleed the line. He said it's a common issue when flying from cold locations (NJ) to warmer destinations (Georgia).
I also get hear the pump activate in flight for a fraction of a second every 20-30 minutes or so, which I suspect points to a leak of some sort.
Keith
Smith
N360JH