Return-Path: Received: from [65.33.163.54] (account ) by logan.com (CommuniGate Pro WebUser 4.0.1) with HTTP id 1883268 for ; Wed, 20 Nov 2002 20:46:22 -0500 From: "Marvin Kaye" Subject: Re: [LML] Re: hydraulic gauge To: "Lancair Mailing List" X-Mailer: CommuniGate Pro Web Mailer v.4.0.1 Date: Wed, 20 Nov 2002 20:46:22 -0500 Message-ID: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit "Lorn H. Olsen" wrote: >>What am I missing? I have been working with mechanics for the last 3 weeks on my hydraulic system and we haven't found the supple or return lines.<< The hydraulic systems are quite different between the LNC2 and the LIV... the LNC2 system uses a reversible pump that's setup to deliver high pressure in one direction (gear up) and low pressure in the other (gear down). The supply and return lines are interchangable, they just trade places depending on which direction you're running the pump. In the gear up mode, the high pressure side is the supply line and the fluid in the low pressure line returns to the tank. In the low pressure (gear down) mode, the low pressure side is the supply and fluid returns via the high pressure lines. On the LIV the pump has a true supply side and return side and only operates in one direction. The switching of the fluid under pressure to the landing gear (and the flaps, BTW) is managed by a hydraulic switch that sends the fluid to one side of the gear cylinders in the gear up mode, and to the other side of the cylinders in the gear down mode. The operating pressure on the LIV is the same regardless of which direction the gear or flaps are moving. The LIV system operates at about 1200psi and the pump is controlled by a single pressure switch. I hope this answers your question.