Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.4.7) with ESMTP id 791404 for rob@logan.com; Sun, 27 May 2001 09:19:39 -0400 Received: from siaag1aa.compuserve.com ([149.174.40.3]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71175U5500L550S0V35) with ESMTP id com for ; Sun, 27 May 2001 09:12:02 -0400 Received: (from mailgate@localhost) by siaag1aa.compuserve.com (8.9.3/8.9.3/SUN-1.9) id JAA14380 for lancair.list@olsusa.com; Sun, 27 May 2001 09:19:22 -0400 (EDT) Date: Sun, 27 May 2001 09:18:57 -0400 From: James Frantz Subject: L-360 Hydraulic Pump Cycling Sender: James Frantz To: "INTERNET:lancair.list@olsusa.com" Message-ID: <200105270919_MC2-D349-6074@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Frequent cycling of the hydraulic pump could be the result of faulty pressure switches but ---- The probable root cause is an internal leak in the hydraulic pump or an internal leak in one of the six cylinders or an internal leak in the gear= dump bypass valve. My Lancair flies for four hours gear up without the hydraulic pump cycling and that is the way it should work when all = internal leaks are eliminated. The problem in trying to eliminate internal leaks is how to determine if the leak is in the pump or one or several of the cylinders or the bypass valve. The troubleshooting process requires isolation of all of the abov= e hydraulic valves and cylinders bringing one at a time back into the syste= m. This requires six hydraulic plugs and a lot of work with the aircraft on= the jack stand. You can eliminate the frequent blurp! Is it worth it? I suppose that depends on how often the system blurps. = Jim Frantz = >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>