Mailing List lml@lancaironline.net Message #62917
From: Chris Zavatson <chris_zavatson@yahoo.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Temp effect on hydraulics
Date: Tue, 04 Sep 2012 19:53:48 -0400
To: <lml@lancaironline.net>
Ed,
Coefficient of Thermal Expansion of hydraulic fluid ~270,000 psi.
Air in the system would make it very soft - think Ideal Gas Law - until the pressure gets really high. It would take a much larger change in volume to get a big change in pressure.
Consider the nose strut.  Pressure goes up as the strut is compressed over several inches.  Now imagine the strut completely filled with fork-oil.  It will still move, but not by much. 
Brakes systems are a different animal. They are not closed systems until the brakes are actually in use. 
Chris
 
Chris Zavatson
N91CZ
360std

From: Ed Gray <egraylaw@swbell.net>
To: lml@lancaironline.net
Sent: Tuesday, September 4, 2012 1:18 PM
Subject: [LML] Re: Temp effect on hydraulics

What is the coefficient of heat expansion on hydraulic fluid?  Seems that
big pressure changes would be caused by trapped air.  Auto brakes don't fail
in low or high temps.  Could it be trapped air in the fluid line to the
sensor?
Ed Gray L360 Nearly complete with test hours, Dallas

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net]
Sent: Tuesday, September 04, 2012 5:01 AM
Subject: lml Digest #3893

        Lancair Mailing List Digest #3893

1) Re: Critical Service Bulletin
    by Silvio Novelli <ppxsn@novellisouza.com.br>
2) Barrett at fly-in
    by "Claudette Colwell" <colwell.ch@gmail.com>
3) Re: Critical Service Bulletin on Cruise RPM
    by Silvio Novelli <ppxsn@novellisouza.com.br>
4) Re: Critical Service Bulletin on Cruise RPM
    by Colyn Case <colyncase@earthlink.net>
5) Re: Thermal influence on Hydraulic Pressure
    by "Danny" <danny@n107sd.com>
6) Re: Thermal influence on Hydraulic Pressure
    by Frederick Moreno <frederickmoreno@bigpond.com>

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