X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 28 Jun 2013 14:34:25 -0400 Message-ID: X-Original-Return-Path: Received: from oproxy9.bluehost.com ([69.89.24.6] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with SMTP id 6353756 for lml@lancaironline.net; Fri, 28 Jun 2013 13:47:28 -0400 Received-SPF: neutral receiver=logan.com; client-ip=69.89.24.6; envelope-from=danny@n107sd.com Received: (qmail 5218 invoked by uid 0); 28 Jun 2013 17:42:40 -0000 Received: from unknown (HELO host295.hostmonster.com) (66.147.240.95) by oproxy9.bluehost.com with SMTP; 28 Jun 2013 17:42:40 -0000 Received: from [98.233.210.64] (port=60500 helo=DannysW7PC) by host295.hostmonster.com with esmtpa (Exim 4.80) (envelope-from ) id 1Uscgx-0001dX-Ua for lml@lancaironline.net; Fri, 28 Jun 2013 11:42:40 -0600 From: "Danny" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Fwd: Hydraulic pump cycling / Replacing dump valve X-Original-Date: Fri, 28 Jun 2013 13:42:33 -0400 X-Original-Message-ID: <085c01ce7426$df458ea0$9dd0abe0$@n107sd.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_085D_01CE7405.5838A990" X-Mailer: Microsoft Outlook 14.0 thread-index: AQGoe3vTjJBHGZl3o7aTr2tVsOvIIpmXUKAQ Content-Language: en-us X-Identified-User: {3234:host295.hostmonster.com:wunderwe:n107sd.com} {sentby:smtp auth 98.233.210.64 authed with danny@n107sd.com} This is a multipart message in MIME format. ------=_NextPart_000_085D_01CE7405.5838A990 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit You're about to embark on some real time consuming fun. If you have one of the old dump valves, they were rated at only about 600 psi as I recall. The ball valve had a Teflon coating that would deform under high pressure and leak. You need a Parker valve rated at 2000 psi or higher. I believe mine is rated at 5000 psi. But, if your dump valve is that hard to get to, maybe you want to check all your gear and door cylinders first. There are six of them so get a handful of AN fitting caps & plugs, jack up your plane and have at it. I'd also suggest installing 2 hydraulic 3000 psi pressure gauges, one on the low pressure side, another on the high side. Cap & plug all of the cylinders, isolate the valve from the pump and then run the pump. If it cycles, the pump has an internal leak. If not, introduce the valve back into the system and run it again. If it cycles, your valve is bad. Then introduce one cylinder at a time, run the pump and see when it cycles. This all takes a lot of time but it's the only way to figure it out. Happy hunting. Danny LNC2-360 Mk-II Nothing is foolproof to the sufficiently talented fool. From: Erik Larson [mailto:asw20747@aol.com] Sent: Friday, June 28, 2013 9:32 AM To: lml@lancaironline.net Subject: [LML] Fwd: Hydraulic pump cycling / Replacing dump valve I have a Legacy, 6 1/2 years, appx 650 hours, we started experiencing momentary hydraulic pump cycling, averaging now every 6-8 minutes for a micro second. There are NO external leaks and NO loss of fluid in the system, so I guess it's time to start trouble shooting to find the internal bypass. Following some previous postings on the issue, it seems that if it's not the cylinders, then the next logical place would be the dump valve. At first glance it looks like getting the dump valve changed out could be quite a job. Anyone that's done it recently care to share some Helpful Hints? It looks like the only way to get to it, is by disassembling the throttle quadrant, even then it looks tight? Any advise on that or general trouble shooting advise for the hydraulic system would be GREATLY appreciated! Erik Larson Legacy/N74FX ------=_NextPart_000_085D_01CE7405.5838A990 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

You’re about to embark on some real time = consuming fun.  If you have one of the old dump valves, they were = rated at only about 600 psi as I recall.  The ball valve had a = Teflon coating that would deform under high pressure and leak.  You = need a Parker valve rated at 2000 psi or higher.  I believe mine is = rated at 5000 psi.  But, if your dump valve is that hard to get to, = maybe you want to check all your gear and door cylinders first.  = There are six of them so get a handful of AN fitting caps & plugs, = jack up your plane and have at it.  I’d also suggest = installing 2 hydraulic 3000 psi pressure gauges, one on the low pressure = side, another on the high side.  Cap & plug all of the = cylinders, isolate the valve from the pump and then run the pump.  = If it cycles, the pump has an internal leak.  If not, introduce the = valve back into the system and run it again.  If it cycles, your = valve is bad.  Then introduce one cylinder at a time, run the pump = and see when it cycles.  This all takes a lot of time but = it’s the only way to figure it out.  Happy = hunting.

 

Danny

LNC2-360 = Mk-II

Nothing is foolproof to the sufficiently = talented fool.

 

From:= = Erik Larson [mailto:asw20747@aol.com]
Sent: Friday, June 28, = 2013 9:32 AM
To: lml@lancaironline.net
Subject: = [LML] Fwd: Hydraulic pump cycling / Replacing dump = valve

 

<= o:p> 

I= have a Legacy, 6 1/2 years, appx 650 hours, we started experiencing = momentary hydraulic pump cycling, averaging now every 6-8 minutes for a = micro second.

 <= /span>

There are NO = external leaks and NO loss of fluid in the system, so I guess it's time = to start trouble shooting to find the internal bypass.  Following = some previous postings on the issue, it seems that if it's not the = cylinders, then the next logical place would be the dump = valve.

 <= /span>

At first glance = it looks like getting the dump valve changed out could be quite a job. =  Anyone that's done it recently care to share some Helpful = Hints?

 <= /span>

It looks like the = only way to get to it, is by disassembling the throttle quadrant, even = then it looks tight?

 <= /span>

Any advise on = that or general trouble shooting advise for the hydraulic system would = be GREATLY appreciated!

 <= /span>

Erik = Larson

Legacy/N74FX<= /o:p>

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