X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 27 Oct 2010 06:31:18 -0400 Message-ID: X-Original-Return-Path: Received: from vms173019pub.verizon.net ([206.46.173.19] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4543264 for lml@lancaironline.net; Tue, 26 Oct 2010 17:35:04 -0400 Received-SPF: pass receiver=logan.com; client-ip=206.46.173.19; envelope-from=lancair403@verizon.net Received: from personalab15f4 ([unknown] [72.64.61.114]) by vms173019.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0LAX004J52LDLG50@vms173019.mailsrvcs.net> for lml@lancaironline.net; Tue, 26 Oct 2010 16:34:26 -0500 (CDT) X-Original-Message-id: <84442BDA9C0841A5A3FC9AC607253D46@personalab15f4> From: "William Rumburg" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Hydraulic Cylinder Rebuild X-Original-Date: Tue, 26 Oct 2010 17:34:14 -0400 MIME-version: 1.0 Content-type: multipart/alternative; boundary="----=_NextPart_000_0025_01CB7534.0322E9C0" X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 This is a multi-part message in MIME format. ------=_NextPart_000_0025_01CB7534.0322E9C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris- My shafts and cylinders were in perfect condition. I smeared the new = O-rings with petroleum jelly prior to installing them on the end caps. = The O-rings are a tight fit into the cylinders and I made a circular = rocking motion while applying just enough force to insert them. My = concern was possible damage to the O-rings when forcing them into the = cylinders and across the snap ring grooves. I considered making sleeves = from clear thin mylar in order to transition them into the cylinders and = across the O-ring grooves without damage but didn't. Have you or anyone = else tried that?=20 All my cylinders are now 'bone dry' during test retractions. Bill Rumburg N403WR (Sonic bOOm)=20 =20 ----- Original Message -----=20 From: Chris Zavatson=20 To: lml@lancaironline.net=20 Sent: Monday, October 25, 2010 3:09 PM Subject: [LML] Re: Hydraulic Cylinder Rebuild Bill, That is the trick. Once apart inspect the shaft very closely for scratches. If there are = any they need to be buffed out. If they remain the weeping will return = shortly. The same goes for the ID of the cylinders bores. Scratches = here will lead to pressure leaking across the piston seal rather than = the external weeping you mentioned. Scratched will tend to damage new = seals, so it is a good idea to remove them when everything is apart. Chris Chris Zavatson N91CZ 30std www.N91CZ.com -------------------------------------------------------------------------= ----- From: William Rumburg To: lml@lancaironline.net Sent: Mon, October 25, 2010 6:00:10 AM Subject: [LML] Hydraulic Cylinder Rebuild After ten years in service, all three door cylinders and two of the = three gear retract cylinders on my 320 were 'weeping' fluid and needed = rebuilding (Bill Harrellson said that his have been in service ten years = with no sign of leaking and that mine are leaking because I'm not flying = enough - he's probably right) The three gear retract cylinders are manufactured by Wolstenholme = Industries and neither I nor a couple of A&P's could determine how to = remove the snap rings at each end. Eventually I saw how. Simply remove = the hose fittings at each end and press the end caps a short distance = into the cylinder to expose the snap rings and they're then easily = removed. Bill Rumburg N403WR (Sonic bOOm) ------=_NextPart_000_0025_01CB7534.0322E9C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Chris-
 
My shafts and cylinders were in perfect condition. I smeared = the new=20 O-rings with petroleum jelly prior to installing them on the end=20 caps. The O-rings are a tight fit into the cylinders and = I made a=20 circular rocking motion while applying just enough force to insert them. = My=20 concern was possible damage to the O-rings when forcing them into the = cylinders=20 and across the snap ring grooves. I considered making sleeves=20 from clear thin mylar in order to transition them into the = cylinders=20 and across the O-ring grooves without damage but didn't. Have you = or anyone=20 else tried that? 
All my cylinders are now 'bone dry' during test=20 retractions.
 
Bill Rumburg
N403WR (Sonic bOOm) 
  
----- Original Message -----
From:=20 Chris=20 Zavatson
Sent: Monday, October 25, 2010 = 3:09=20 PM
Subject: [LML] Re: Hydraulic = Cylinder=20 Rebuild

Bill,
That is the trick.
Once apart inspect the shaft very closely for = scratches.  If=20 there are any they need to be buffed out.  If they remain the = weeping=20 will return shortly.  The same goes for the ID of the cylinders=20 bores.  Scratches here will lead to pressure leaking across = the=20 piston seal rather than the external weeping you mentioned.  = Scratched will tend to damage new seals, so it is a good idea to = remove them=20 when everything is apart.
Chris
 
Chris Zavatson
N91CZ
30std

From: William Rumburg=20 <lancair403@verizon.net>
To: = lml@lancaironline.net
Sent: Mon, October 25, 2010 = 6:00:10=20 AM
Subject: [LML] = Hydraulic=20 Cylinder Rebuild

After ten = years in service,=20 all three door cylinders and two of the three gear retract cylinders = on my 320=20 were 'weeping' fluid and needed rebuilding (Bill Harrellson said that = his have=20 been in service ten years with no sign of leaking and that mine are=20 leaking because I'm not flying enough - he's probably = right)
The three gear retract = cylinders are=20 manufactured by Wolstenholme Industries and neither I nor a = couple of=20 A&P's could determine how to remove the snap rings at each = end.=20 Eventually I saw how. Simply remove the hose fittings at each end and = press=20 the end caps a short distance into the cylinder to expose the = snap=20 rings and they're then easily removed.
 
Bill Rumburg
N403WR (Sonic=20 bOOm) 
------=_NextPart_000_0025_01CB7534.0322E9C0--