Date: Thu, 05 Jul 2001 10:29:44 -0400
From: ricargente@cs.com
To: lancair.list@olsusa.com
Subject: LNC2: Hydraulic Cylinders
Message-ID: <483DA9EA.2668FE8C.104B1EDC@cs.com>
Content-Type: text/plain; charset=iso-8859-1
Reply-To: lancair.list@olsusa.com

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Last weekend, we were practicing formation flying with another Lancair and were just having a great time.  However, the pilot flying the other Lancair mentioned that my main gear doors were opening slightly.  It would tuck in briefly, then sag again after a few minutes.   You can imagine how ugly this may look not to mention the drag penalty that comes with this ugliness.   Please note, I have over 200 hours on 360ZR now.

I decided to remove the main's hydraulic cylinders and the nose gear door cylinder (badly leaking) and overhaul these suckers.   Overhaul kits cost $7 each from Vern's Lancair supply store.   On the main hydraulic cylinders, you'll need to remove both AN fittings in order to open both ends.  Snap ring tool makes the whole operation a breeze.    Inside the cylinders, around the  O-rings, I noticed black residue, presumably from the O-rings.  I cleaned the whole assembly thoroughly and installed the new O-rings.  

You don't need to remove the AN fittings from the gear door cylinders.  

Assembled everything back together and tested the system.   While on jacks, I sucked up the gears and turned the master off.  After 30 minutes, gear/gear doors are still tight and no noticeable sagging at all.   Just for fun, I'm going to overhaul the nose gear cylinder and the other two gear door cylinders next week.  

As an aside, about three weeks ago, after takeoff, I called for gear-up but gears stayed down.   Played around with the switches, dump valve, CB, etc, etc, but system was completely dead.  I landed and went to work (job).  Next day, eager to do some trouble shooting, I put the plane on jacks and what do you know?  Everything's working fine...  Bummer.  Right now, it could be the gear sw or the pressure switches, or the gear relays.  I ordered the newest style pressure switches anyway and will install them when they arrive today.  Maybe I'll also replace the gear relays (starter relays).  

Rick Argente
N360ZR

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