Mailing List lml@lancaironline.net Message #38644
From: Gary Edwards <gary21sn@hotmail.com>
Sender: <marv@lancaironline.net>
Subject: Re: Electrical /Hydraulic systemquestionslancair235/320
Date: Thu, 23 Nov 2006 09:28:47 -0500
To: <lml>
Chris, Scott, Bob, Earl, Randy, Et Al 
 
Chris, as you say, I will not attempt to try either of those suggestions for slowing the nose gear extension.
 
The kit number of my plane from late 1987 was 212.  I have the original pump and it has worked fine with no problems (as I reported on this subject on the LML on 8/29/06.  In November 1999 I sent my pump to Oildyne (Ed Vanhecky not there now - sorry to say - very knowledgeable) for their recommended upgrades ($125).  They installed the "back pressure modification". 
 
The pump is number 1427 which indicates the 142 day of 1987.  Scott, your original pump is number 829 which is the 82nd day of 1989.  I do not have handy the original part numbers before the modification.  The revised part number after the "back pressure modification" is:  R-640788 and 108AA19-ALBSP-3VT.  Earl, the numbers are on the side of the pump, so good luck reading them (maybe with a mirror).
 
My pump operates as described by Bob.  With the reservoir filled to the full mark on the dip stick when the gear is retracted, I have never had any fluid overflows.  It is noted that there is not much difference in distance between the high and low marks on the dip stick in the small round reservoir.  With that in mind it doesn't appear that very much fluid moves to and from the reservoir. 
 
Gary Edwards
LNC2 N21SN
Medford, Oregon
 
  
Many moons ago I read about changes that were made in the pump supplied
to Lancair.  Oildyne has many options available.  We even used one here
at work for a back-up steering system.  I am really only familiar with
the last supplied configuration.  I am curious to know what part number
was supplied in 235 kits and when the change may have occured.  Is your
pump the original supplied with the kit?  The part number will reveal
any configuration differences.  I can certainly envision a configuration
that bleeds off fluid easily in both directions to produce the behavior
you describe.  If there are different versions out there, knowing what
they are will help in discussing hydraulic system issues. 
Chris
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