X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Sat, 14 Oct 2006 16:36:06 -0400 Message-ID: X-Original-Return-Path: Received: from mail.glasair.org ([65.75.24.102] verified) by logan.com (CommuniGate Pro SMTP 5.1c.6) with ESMTPS id 1466036 for lml@lancaironline.net; Sat, 14 Oct 2006 11:16:33 -0400 Received-SPF: none receiver=logan.com; client-ip=65.75.24.102; envelope-from=Bruce@glasair.org Received: from bruce1 by mail.glasair.org (VisNetic.MailServer.v8.5.0.8) with ESMTP id SZE09513 for ; Sat, 14 Oct 2006 11:16:13 -0400 From: "Bruce Gray" X-Original-To: "'Lancair Mailing List'" Subject: RE: [LML] Re: LNC2 Gear Leak on High (Up) Side X-Original-Date: Sat, 14 Oct 2006 11:18:14 -0400 X-Original-Message-ID: <005c01c6efa3$f7c728d0$0a01a8c0@bruce1> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_005D_01C6EF82.70B588D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_005D_01C6EF82.70B588D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Sounds like you have a high to low cylinder leak. Disconnect each low = side and plumb to a coke bottle or other suitable container. Retract the = gear. After the gear is up mark the fluid level in each bottle. Over time the = bad cylinder will leak fluid from the down side into it's respective = container.=20 =20 =20 Bruce www.glasair.org =20 -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Steve Rosenzweig Sent: Saturday, October 14, 2006 9:56 AM To: Lancair Mailing List Subject: [LML] Re: LNC2 Gear Leak on High (Up) Side 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??'' =20 Thanks =20 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 =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 =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 =20 One more LNC2 gear data point. =20 Regards, Clark Baker LNC2 360, 710hrs TT =20 _____ =20 -- For archives and unsub http://mail.lancaironline.net/lists/lml/ ------=_NextPart_000_005D_01C6EF82.70B588D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Sounds like=20 you have a high to low cylinder leak. Disconnect each low side and plumb = to a=20 coke bottle or other suitable container. Retract the gear. After the = gear is=20 up mark the fluid level in each bottle. Over time the bad cylinder = will=20 leak fluid from the down side into it's respective container.=20
 
 

Bruce
www.glasair.org
 

-----Original Message-----
From: = Lancair Mailing=20 List [mailto:lml@lancaironline.net] On Behalf Of Steve=20 Rosenzweig
Sent: Saturday, October 14, 2006 9:56 = AM
To:=20 Lancair Mailing List
Subject: [LML] Re: LNC2 Gear Leak on = High (Up)=20 Side

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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