X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Sat, 14 Oct 2006 09:55:44 -0400 Message-ID: X-Original-Return-Path: Received: from vms046pub.verizon.net ([206.46.252.46] verified) by logan.com (CommuniGate Pro SMTP 5.1c.6) with ESMTP id 1465293 for lml@lancaironline.net; Sat, 14 Oct 2006 00:12:40 -0400 Received: from OLDHOME ([71.105.203.74]) by vms046.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep 9 2005)) with ESMTPA id <0J73003OXYC9MEJ0@vms046.mailsrvcs.net> for lml@lancaironline.net; Fri, 13 Oct 2006 23:12:14 -0500 (CDT) X-Original-Date: Fri, 13 Oct 2006 21:12:07 -0700 From: "Steve Rosenzweig" Subject: Re: [LML] LNC2 Gear Leak on High (Up) Side X-Original-To: "Lancair Mailing List" X-Original-Message-id: <001e01c6ef46$ea7cbb70$6501a8c0@OLDHOME> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Mailer: Microsoft Outlook Express 6.00.2900.2869 Content-type: multipart/alternative; boundary="----=_NextPart_000_001B_01C6EF0C.3DA83E40" X-Priority: 3 X-MSMail-priority: Normal References: This is a multi-part message in MIME format. ------=_NextPart_000_001B_01C6EF0C.3DA83E40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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_001B_01C6EF0C.3DA83E40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
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 same=20 type of pump shown in Clark's attachment (series 108 OilDyne = pump).  I tore=20 it down and replaced all the internal O rings, reinstalled it and it = continued=20 to do the same thing.  I then disconnected the extend side of each = gear=20 actuator and plugged it and then turned power on in an attempt to = isolate a=20 leaking cylinder.  But that didn't help either.  Now I didn't = check=20 the door actuators which are also T'd off the same lines.  I'd say = the=20 actuators and pump are about 5 years old.  Anyone have any other=20 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 = 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 = 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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