X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 24 Sep 2009 22:06:46 -0400 Message-ID: X-Original-Return-Path: Received: from web36902.mail.mud.yahoo.com ([209.191.85.70] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with SMTP id 3862843 for lml@lancaironline.net; Tue, 22 Sep 2009 19:46:35 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.85.70; envelope-from=chris_zavatson@yahoo.com Received: (qmail 51339 invoked by uid 60001); 22 Sep 2009 23:46:01 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=hb+e6DQeSUkg2JGV8qIoA5qyo2aYEaDyNpnEwJlW6hC2Tq1Mq867B0J9IVKVjpy/zf0/COK5dNf+NzVLm8d0so521ErkKTcxsSGtvInQn1uPqScBtBgQn+nyZ85eOU5K2u5t3DZOTfM0GTa0ZLEAyFvZgv3vrWXRb9k/wW19wrg=; X-Original-Message-ID: <342969.51125.qm@web36902.mail.mud.yahoo.com> X-YMail-OSG: nRVhsVQVM1kKe8m6oeo9YW8Y8lOzZMmCZGNwT1iossxq0WLk5.zJ3u1n.dC_H1BObJNBbYe4Uxz7Q17S7nRAHWauQ4Yt.UB7_AP7sxUOOOy5vC.wXB_wJLJPScqXqiVmW0d6DG58abkj2T28oH5Yjszi44DhpWM6sTxqWp4g_qj8VEwObBvCSL1fbKFpmMy1nRpBYTx2gx4sRuqz4SOwypc_h4OjrjntVhFr7NVcbDaV6_B9H_elaFuMtJeoY1Wy.vr0tMrrBwaua_QJvR_HENbEVWiP8AiIULo6mghg3NWRsqfc6GsbDSYij3Gc59ArmzDcmoRCiayefRxyIXFPPKNFjyifJEc6uhjar5XEh5o3IOnvKlcWzVE- Received: from [149.32.224.33] by web36902.mail.mud.yahoo.com via HTTP; Tue, 22 Sep 2009 16:46:01 PDT X-Mailer: YahooMailRC/157.18 YahooMailWebService/0.7.347.2 References: X-Original-Date: Tue, 22 Sep 2009 16:46:01 -0700 (PDT) From: Chris Zavatson Subject: Re: [LML] LNC2 Gear Up & Down Problems X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1133925597-1253663161=:51125" --0-1133925597-1253663161=:51125 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Lorn,=0AIf you have pressure in both high and low circuits then both tappet= valves within the pump are closed at the same time.=A0 When the pump is po= wered, the spool valve pushes one of the valves off its seat to allow retur= n flow from the opposing circuit.=A0 For some reason your spool valve is no= t holding the poppet valve open after the=A0pump shuts down.=A0 Does your s= pool valve have an O-ring?=A0 It is the friction of this O-ring that keeps = the spool valve from moving on its own.=A0 It is actually rather stiff.=A0 = There does exist a spool valve for our model pumps without an O-ring.=A0 Th= e long term fix would be to figure out why some systems=A0are locking up on= both sides while others do not.=A0 The first thing I would check is fricti= on in the spool valve.=A0 =0AA potential short term fix would be a momentar= y bypass on the pressure switches.=A0 Having pressure on both sides at the = same time is not a good situation.=A0 While parked on the ground, the high = side circuit should be vented.=A0 Similarly, when in flight the low side is= vented.=A0 This prevents build up of pressure on the non-utilized side of = the system.=A0 These operating characteristics are shown in a series of vid= eo clips on the following page.=A0 =0A=A0=0Ahttp://www.n91cz.com/Hydraulics= /Lancair_Hydraulics.htm=0A=A0=0AI hope you are able to get rid your your sy= stem's gremlins once and for all.=A0 I know they have caused you much grief= over the years.=0A=A0=0AChris Zavatson=0AN91CZ=0AL360std=0Awww.N91CZ.com= =0A=0A=0A --0-1133925597-1253663161=:51125 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable

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Lorn,

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If y= ou have pressure in both high and low circuits then both tappet valves with= in the pump are closed at the same time.&= nbsp; When the pump is powered, the spool valve pushes one of the va= lves off its seat to allow return flow from the opposing circuit. For some reason your spool valve is n= ot holding the poppet valve open after the pump shuts down. Does your spool valve have an O-ring?<= SPAN style=3D"mso-spacerun: yes"> It is the friction of this O= -ring that keeps the spool valve from moving on its own. It is actually rather stiff. There does exist a spool valve for our model = pumps without an O-ring. The long term fix would be to figure out why some systems are = locking up on both sides while others do not. The first thing I would check is friction in the spool valve.&nb= sp;

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A potential short term fix would be a momentary bypass = on the pressure switches. Ha= ving pressure on both sides at the same time is not a good situation. While parked on the ground, the h= igh side circuit should be vented. = Similarly, when in flight the low side is vented. This prevents build up of pressure on the non-= utilized side of the system. These operating characteristics are shown in a series of video clips on th= e following page.

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htt= p://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm

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I hope you ar= e able to get rid your your system's gremlins once and for all. I kno= w they have caused you much grief over the years.

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Chris Zavatso= n

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N91CZ

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L360std

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