Mailing List lml@lancaironline.net Message #37957
From: Robert R Pastusek <rpastusek@htii.com>
Sender: <marv@lancaironline.net>
Subject: IV/IV-P Main Gear Legs
Date: Tue, 03 Oct 2006 22:30:41 -0400
To: <lml@lancaironline.net>
Builders,
 
My wife says I am often the last person in the world to figure out what everyone else knows and takes for granted, but I made a "discovery" this weekend that is probably well known to all but me? Just in case it isn't, here's the scoop.
 
I attempted to remove the machined aluminum axle mounting brackets from the lower gear legs of my LIV-P to replace the nylaflow with braided stainless-covered tubing. Mine is a 1999 era kit, but has never been parked outside/in the rain as far as I know. Even so, I had to tap out the two 1/4" retaining bolts with a hammer because corrosion had built up around the areas where the aluminum axle mount joined the steel gear leg--my first clue that there might be a problem, and not visible at all from an outside inspection. The aluminum mount was well corroded to the gear leg, but I was able to free it by applying penetrating oil and a heat gun, and using a piece of plastic pipe over the axle to rotate and loosen the mount on the gear leg.
 
When I got it off, I found that water had penetrated between the steel gear leg and the aluminum axle mount, and set up some serious corrosion between these parts. This is a natural path for water to run down the gear leg in the rain, or during washing.  Further, there is no way for any water to drain out of this area. To correct this, I drilled a "weep hole" on the inside face of the axle mount about an inch above the existing brake line fitting. I determined-the actual location by measuring the depth of the interior clearance hole for the brake line fitting and transferring this measurement to the outside of the part. I treated these parts for corrosion resistance, installed my new brake lines and reassembled, using a bit of clear silicone sealant around the gear leg/axle mount interface.
 
Has anyone else seen this? It seems to me that any airplane parked out in the rain is sure to fill these little corrosion reservoirs in short order.
 
Bob Pastusek
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