X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 08 Feb 2008 15:13:56 -0500 Message-ID: X-Original-Return-Path: Received: from web54402.mail.yahoo.com ([206.190.49.132] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with SMTP id 2720427 for lml@lancaironline.net; Thu, 07 Feb 2008 23:48:38 -0500 Received: (qmail 96051 invoked by uid 60001); 8 Feb 2008 04:48:37 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=eWmyhyEV5I6EF9UzuQx2si32bLZT6/wnw+YqibaL7/1yGgu6FdG88wWcJXfN3JQYIp429Ore+55CNb59A2ZQvwu6yWJSwdHyvgd9LUCBBmaFWwDsCegvRq6slvyy17BQiuLOejVT3SnD1E2rLDiVAlRi9EW/TXO34+EXkzvgaPw=; X-YMail-OSG: Sgudpj4VM1mVPPaYzt4cwQ7XLWqzVe8DDJVNvfLRXC5s_ql7qgpjAuqccBPJgCIGE_5KH_dnDwecF3V__AohF2FJ3hagCxSswwA9Zrz.HcdLbQ4tvX16NwUkgBqoQg-- Received: from [76.8.220.18] by web54402.mail.yahoo.com via HTTP; Thu, 07 Feb 2008 20:48:37 PST X-Original-Date: Thu, 7 Feb 2008 20:48:37 -0800 (PST) From: randy snarr Subject: Re: [LML] FW: [LML] 235/320/360 gear dump valve idea X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1812456172-1202446117=:95997" Content-Transfer-Encoding: 8bit X-Original-Message-ID: <692698.95997.qm@web54402.mail.yahoo.com> --0-1812456172-1202446117=:95997 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Thanks Larry, I will look at my pump again tomorrow. I did not know there was already a fitting for a return line. Is the return port on the pump simply a connection to the resevoir? Randy. LHenney wrote: v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} st1\:*{behavior:url(#default#ieooui) } Randy, Hold off on the machine work. Your pump is designed with a third port (between the two now in use). It is threaded and ready for your return line. A ¼ “ tubing can be installed as a down tube in the tank (mine came with the tube installed). Also, Randy Stuarts idea of a T shuttle sounds very, very interesting. I don’t completely know what a T shuttle valve is however. Thus, I’m grappling with check valve analogies and getting a lot of “how would that work?” thoughts. Does this mean pressure on up circuit triggers opening of shuttle from down circuit, therefore T goes to third port??? I’m tempted to like this idea. Additionally, could second T also tie in to third port and allow 3 way dump common path to reservoir. Please tell us more R. Stuart….. Larry Henney N360LH Much less chirping lately after changing out pump O rings; Lancair also got more pressure gauges in stock and shipped mine. --------------------------------- From: Sky2high@aol.com [mailto:Sky2high@aol.com] Sent: Wednesday, February 06, 2008 2:49 PM To: lml@lancaironline.net Subject: Re: [LML] 235/320/360 gear dump valve idea Randy, Remember that the reservoir needs a small vent hole so that air pressure or vacuum does not build up in the reservoir itself. Usually the vent is in the filler cap or its threads. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Pilot not TSO'd, Certificated score only > 70%. In a message dated 2/6/2008 11:29:13 A.M. Central Standard Time, randylsnarr@yahoo.com writes: With the way the hydraulic system is currently designed, you equalize the pressure on the high and low sides when it is opened. For those of us who have pressure gauges, you can see that you can have significant pressure on the system even when the valve is opened. I want to be able to not only equalize the pressure between the high and low sides of the hydraulic system with the dump valve but also release the pressure on both sides. Today I purchased a 3 way valve to do just that. The idea is to open the valve connecting the high and low sides and also releasing the pressure back to the tank. I will most likely run a low pressure line like nylaflow back to the pump and make spin up a custom fitting on the lathe out of aluminum to go into the dipstick hole and terminate the return line there. I will make a needle dipstick checker that will screw into the same fitting for checking fluid level. If you wanted to do it the easy way, you could always just dump the low pressure line out the belly of the airplane onto the ground. It would take very little fluid to drop the pressure and there would be no need to deal with connecting the low pressure fluid line to the tank. I hate pulling the airplane out of a cool hanger into the warm sunshine and watching the gear pressures rise to 6-700 lbs before the master switch is turned on! We all know what happens when they hit 900. Yep no gear retraction as the upper limit has been tripped by the system pressure. My new valve would fix that!!! I hope... --------------------------------- Who's never won? Biggest Grammy Award surprises of all time on AOL Music. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. --0-1812456172-1202446117=:95997 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Thanks Larry,
I will look at my pump again tomorrow. I did not know there was already a fitting for a return line. Is the return port on the pump simply a connection to the resevoir?

Randy.

LHenney <LHenney@charter.net> wrote:
Randy,
 
Hold off on the machine work.  Your pump is designed with a third port (between the two now in use).  It is threaded and ready for your return line.  A ¼ “ tubing can be installed as a down tube in the tank (mine came with the tube installed).
 
Also, Randy Stuarts idea of a T shuttle sounds very, very interesting.  I don’t completely know what a T shuttle valve is however.  Thus, I’m grappling with check valve analogies and getting a lot of “how would that work?” thoughts.   Does this mean pressure on up circuit triggers opening of shuttle from down circuit, therefore T goes to third port???  I’m tempted to like this idea.  Additionally, could second T also tie in to third port and allow 3 way dump common path to reservoir.  Please tell us more R. Stuart…..
 
Larry Henney
N360LH
Much less chirping lately after changing out pump O rings; Lancair also got more pressure gauges in stock and shipped mine.
 
From: Sky2high@aol.com [mailto:Sky2high@aol.com]
Sent: Wednesday, February 06, 2008 2:49 PM
To: lml@lancaironline.net
Subject: Re: [LML] 235/320/360 gear dump valve idea
 
Randy,
 
Remember that the reservoir needs a small vent hole so that air pressure or vacuum does not build up in the reservoir itself.  Usually the vent is in the filler cap or its threads.
 
Scott Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

Pilot not TSO'd, Certificated score only > 70%.
 
 
In a message dated 2/6/2008 11:29:13 A.M. Central Standard Time, randylsnarr@yahoo.com writes:
With the way the hydraulic system is currently designed, you equalize the pressure on the high and low sides when it is opened. For those of us who have pressure gauges, you can see that you can have significant pressure on the system even when the valve is opened. I want to be able to not only equalize the pressure between the high and low sides of the hydraulic system with the dump valve but also release the pressure on both sides.

Today I purchased a 3 way valve to do just that. The idea  is to open the valve  connecting  the high and low sides and also releasing the pressure back to the tank.
I will most likely run a low pressure line like nylaflow back to the pump and make spin up a custom fitting on the lathe out of aluminum to go into the dipstick hole and terminate the return line there. I will make a needle dipstick checker that will screw into the same fitting for checking fluid level.
If you wanted to do it the easy way, you could always just dump the low pressure line out the belly of the airplane onto the ground. It would take very little fluid to drop the pressure and there would be no need to deal with connecting the low pressure fluid line to the tank.

I hate pulling the airplane out of a cool hanger into the warm sunshine and watching the gear pressures rise to 6-700 lbs before the master switch is turned on! We all know what happens when they hit 900. Yep no gear retraction as the upper limit has been tripped by the system pressure.
My new valve would fix that!!!
I hope...
 



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