X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Sat, 14 Oct 2006 16:36:47 -0400 Message-ID: X-Original-Return-Path: Received: from bay0-omc2-s40.bay0.hotmail.com ([65.54.246.176] verified) by logan.com (CommuniGate Pro SMTP 5.1c.6) with ESMTP id 1466065 for lml@lancaironline.net; Sat, 14 Oct 2006 11:34:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.246.176; envelope-from=n320g@hotmail.com Received: from hotmail.com ([64.4.56.87]) by bay0-omc2-s40.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.1830); Sat, 14 Oct 2006 08:34:08 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sat, 14 Oct 2006 08:34:08 -0700 X-Original-Message-ID: Received: from 71.142.234.25 by BAY101-DAV15.phx.gbl with DAV; Sat, 14 Oct 2006 15:34:07 +0000 X-Originating-IP: [71.142.234.25] X-Originating-Email: [n320g@hotmail.com] X-Sender: n320g@hotmail.com From: "N320GG" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: LNC2 Gear Leak on High (Up) Side X-Original-Date: Sat, 14 Oct 2006 08:34:05 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001E_01C6EF6B.826787C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-OriginalArrivalTime: 14 Oct 2006 15:34:08.0201 (UTC) FILETIME=[30628390:01C6EFA6] X-Original-Return-Path: n320g@hotmail.com This is a multi-part message in MIME format. ------=_NextPart_000_001E_01C6EF6B.826787C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Steve, welcome to the club, there is lots of information about this in = the archives. Buy yourself lots of plugs so you can isolate each = cylinder until you find the problem one. Keep those plugs handy because = you will be using them a lot. Gary Melton N320GG LNC2 ----- Original Message -----=20 From: Steve Rosenzweig=20 I've had the same problem on my LNC360 with the pump cycling on for an = instant, about every 20-30 seconds. I have the same type of pump shown = in Clark's attachment (series 108 OilDyne pump). I tore it down and = replaced all the internal O rings, reinstalled it and it continued to do = the same thing. I then disconnected the extend side of each gear = actuator and plugged it and then turned power on in an attempt to = isolate a leaking cylinder. But that didn't help either. Now I didn't = check the door actuators which are also T'd off the same lines. I'd say = the actuators and pump are about 5 years old. Anyone have any other = suggestions for eliminating this hydraulic cycling??'' Thanks Steve Rosenzweig Lancaster, CA LNC360 ----- Original Message -----=20 From: Clark Baker=20 To: Lancair Mailing List=20 Sent: Tuesday, August 22, 2006 3:03 PM Subject: [LML] LNC2 Gear Leak on High (Up) Side The hydraulic pump in my 360 started to "burp" (ie, run for an = instant) in flight more than the usual once every 20-30 minutes or so. = I could see the High side (UP) pressure going down, forcing the pump to = run for an instant to repressurize the system. After a short period = where the problem went away, it then returned, with the pump cycling = much too often (about every couple of minutes). There was no evidence = of an External leak and the Low side held pressure fairly well.=20 As my gear retract cylinders were about 10year old Matcos, that I = have rebuilt at least once, I decided to install new cylinders now made = by Wohlsenholm, who reportedly makes high quality components. I also = replaced the original gear door cylinders with new ones (I had already = installed the heavy duty dump valve).=20 Now, the system would hold Low pressure for days, something it would = never do before. But, the Hi side problem was unchanged. I = disassembled the hydraulic pump and found a torn O-Ring on the Hi Side = check valve (#8) on the attached drawing. After replacing all the = hydraulic pump seals, the pump did not burp at all on a 20 minute test = flight.=20 One more LNC2 gear data point. Regards, Clark Baker LNC2 360, 710hrs TT =20 -------------------------------------------------------------------------= --- -- For archives and unsub http://mail.lancaironline.net/lists/lml/ ------=_NextPart_000_001E_01C6EF6B.826787C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Steve, welcome to the club, there is lots of = information about=20 this in the archives.  Buy yourself lots of plugs so you can = isolate each=20 cylinder until you find the problem one.  Keep those plugs handy = because=20 you will be using them a lot.
 
Gary Melton
N320GG LNC2
----- Original Message -----
From:=20 Steve=20 Rosenzweig

I've had the same problem on my = LNC360 with the=20 pump cycling on for an instant, about every 20-30 seconds.  I = have the=20 same type of pump shown in Clark's attachment (series 108 OilDyne = pump). =20 I tore it down and replaced all the internal O rings, reinstalled it = and it=20 continued to do the same thing.  I then disconnected the extend = side of=20 each gear actuator and plugged it and then turned power on in an = attempt to=20 isolate a leaking cylinder.  But that didn't help either.  = Now I=20 didn't check the door actuators which are also T'd off the same = lines. =20 I'd say the actuators and pump are about 5 years old.  Anyone = have any=20 other suggestions for eliminating this hydraulic = cycling??''
 
Thanks
 
Steve Rosenzweig
Lancaster, CA
LNC360
----- Original Message -----
From:=20 Clark Baker=20
Sent: Tuesday, August 22, = 2006 3:03=20 PM
Subject: [LML] LNC2 Gear Leak = on High=20 (Up) Side

The hydraulic pump in my 360 started to "burp" (ie, run for an = instant)=20 in flight more than the usual once every 20-30 minutes or so.  = I could=20 see the High side (UP) pressure going down, forcing the pump to run = for an=20 instant to repressurize the system.  After a short period where = the=20 problem went away, it then returned, with the pump cycling much too = often=20 (about every couple of minutes).  There was no evidence of an = External=20 leak and the Low side held pressure fairly well.
 
As my gear retract cylinders were about 10year old Matcos, that = I have=20 rebuilt at least once, I decided to install new cylinders now made = by=20 Wohlsenholm, who reportedly makes high quality components.  I = also=20 replaced the original gear door cylinders with new ones (I had = already=20 installed the heavy duty dump valve).
 
Now, the system would hold Low pressure for days, something it = would=20 never do before.  But, the Hi side problem was unchanged.  = I=20 disassembled the hydraulic pump and found a torn O-Ring on the Hi = Side check=20 valve (#8) on the attached drawing.  After replacing all the = hydraulic=20 pump seals, the pump did not burp at all on a 20 minute test flight. =
 
One more LNC2 gear data point.
 
Regards,
Clark Baker
LNC2 360, 710hrs TT
 

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