Mailing List lml@lancaironline.net Message #25888
From: <edechazal@comcast.net>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Re: LNC2 Vacuum failure and Boost pump problem
Date: Wed, 29 Sep 2004 22:23:35 -0400
To: <lml@lancaironline.net>
Here's the upshot on these two problems:  both builder (yours truly) error.
 
The Vacuum failure - As a couple of people suggested, we checked the pump function directly, it was sucking and blowing.  Hmmm.  Squeal was still there, no vacuum in the system according to the gage and the gyro, although the gyro did move slightly.   Looking at the regulator under the header tank we say one port open, the other having the usual hose attached.  Hmmm.   Then it hit me later.  I bet that mysterious little blue cap I found by the rudder pedals must have been capping that open port on the regulator.  I was working up there during the annual.  That certainly explains the symptoms and when plugged back in, everything worked fine.  Note to self:  that cap and its brother on the vacuum filter port #2 can pop off easily when the engine is not running.  Find a more positive attachment method.
 
The Fuel pump problem - Yes, I put the new pump in backwards.  When I unpacked the new pump it looked just like mine and so I installed it that way.  I had not noticed the cast in words 'in' and 'out' above each port until later when I looked at the old pump, which just reinforced my belief that I put the new one in correctly.   I used the bypass port as reference and failed to notice that it was switchable to the opposite side by moving the plug.  I did notice that the decals seemed reversed on the pump body, but thought nothing of it.  I'll pay for my mistake with having to remove the canopy and header tank again to get at the pump.
 
Lessons:  Whenever you have a wrench or screwdriver in your hand, think about what you're doing.  Also, at the smallest puzzling thing (occurred in both instances above) stop and think it through.  Finally, in case that's not enough, after changes, such as an annual, test on the ground and in the air in safe conditions such as good day VFR. 
 
Regards,
Ed de Chazal
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