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h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=ny7dSykGdJ5FzhWpVVK29x1j4o/G6ATdJisi7bsxQugHwbQsq2bviM7Od2Hwb5AyVI1tHNwRWTb0LujhvQ+UYmVFfn+gzGws7x7JUFzEwDXvqlTDdPzdg6BH+Nhia8Nsv1V6Aka4eAGvfwVlBypd1LWhM/HTdlyApGKxee2ORCs=; X-Original-Message-ID: <26638.1655.qm@web112701.mail.gq1.yahoo.com> X-YMail-OSG: e.EGKN4VM1kUiV0dmbrHQGPqfSQYEfxv.kKNxp0W6OovXKO dv1No_nNxdZciPGqbY2qb7cJ53b5AuKj93RRF5NmU2uv2ulLXlXRwxd029mH OUq_jwjF83bUFQNltXPVo0DJpppcv5vWYQOrCc88oa1HXXR8fX5dGzk0anMB .q0u0FQXrrw4XPIgWtWupRhfaIAf0.x4wTwJlmX7VHw4YKsWM7VlhfzV7hsi FQNowSVCM97NSyuM3JjQz9XmneKx5gMrqH8FN86qDcOo7HrD47yXOVPDniN6 SyxGkJgXcfegNokKLuqsDqQfLCsNTn9bshO3D.5Vk00PpnXCCiO0r00HDpD4 DP6nkxjeV._szZRjvVmcfPhRk.khyKTcq4vxZ58xraL9wQoY5ZBw2KRs- Received: from [98.185.51.168] by web112701.mail.gq1.yahoo.com via HTTP; Mon, 18 Apr 2011 20:58:23 PDT X-Mailer: YahooMailRC/559 YahooMailWebService/0.8.110.299900 References: X-Original-Date: Mon, 18 Apr 2011 20:58:23 -0700 (PDT) From: TOM GARDINER Subject: Re: [LML] Re: Gear operation fix for the LNC2 X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1550552429-1303185503=:1655" --0-1550552429-1303185503=:1655 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Chris,=0A=0AYou are right, looking at the drawing from Oildyne (I posted so= me time back) I =0Aagree that the low pressure poppet needs to remain open = and it does so since the =0Apressurized side keeps the spool forced up agai= nst the poppet by overcomming the =0Aspring force.=A0 If the high side leak= s to zero then the spool will center but =0Aonly then.=A0 So it could be ar= gued why bother with the extra springs at all.=A0 =0AOildyne's response to = that was that it prevents sticking of the spool.=A0 I might =0Areconsider a= nd remove the springs if I notice the system missbehaving, so far it =0Ahas= not,.=A0 My fallback right now is the three way dump valve.=A0 =0A=0A=0AWh= at took me here in the first place was=A0 that I was getting pressurization= on =0Athe low side that was either due to a bad bypass valve, expansion or= leakage =0Aacross the spool,=A0which was not cracking the relief valve (I = subsequently =0Aremoved that valve which allows all fluid to vent to the ta= nk immediatly on the =0Alow side) There is no need for this valve since the= low side is not providing a =0Aretaining function=0A=0ATom=0A=0A=0A=0A=0A_= _______________________________=0AFrom: Chris =0A= To: lml@lancaironline.net=0ASent: Mon, April 18, 2011 8:56:21 PM=0ASubject:= [LML] Re: Gear operation fix for the LNC2=0A=0A=0ATom,=0APlease be careful= l with system changes. =A0I still sounds like you have designed =0Ain the v= ery condition we seek to avoid. =A0The spool must keep the poppet valve =0A= open else you seal off the side that needs to remain at zero pressure. =0A= =A0Wolfgang's circuit will undo this undesirable condition once the "zero s= ide" =0Ahas been pressurized enough to close the pressure switch. =A0Until = then however, =0Athe net working pressure of the system is reduced (net=3Dh= igher side pressure =0Aminus lower side pressure). =A0It also adds wear and= tear by requiring additional =0Apump cycles to restore the unlocked condit= ion. =A0Best to keep the spool where it =0Awas last commanded, the way the = pump was designed to do. =A0The symmetric spool =0Aavoids installation erro= rs - a good thing (I would really like to examine =0Aschematics and drawing= s to look for any unintended consequences). =A0Pressure =0Agauges should be= considered a must-have.=0AIf your pump now has some new way of keeping the= non-working side from becoming =0Apressurized, please elaborate. =A0In all= seriousness, we just want to make sure =0Ayou don't end up in one of those= you-tube videos.=0A=0AChris Zavatson=0AN91CZ=0A360std=0Awww.N91CZ.net=0A= =0ASent from my iPad=0A=0AOn Apr 18, 2011, at 9:09 AM, TOM GARDINER wrote:=0A=0A=0AFolks,=0A>=A0=0A>As I posted some time back, the= re=A0is a fix for the spool getting stuck in one =0A>position or the other.= =A0 Oildyne offers additional springs and a symmetric spool =0A>(not the or= iginal symmetric spool)=A0 The alternative spool is ported on both =0A>side= s to allow fluid to move freely to tank when pushing excess blind end fluid= =0A>back to tank.=A0 (The other side being ported does not really matter)= =A0 The springs =0A>which are quite heavy will certainly center the spool a= nd take it off the =0A>poppets and bypass relief valve after the pump is de= -energized.=A0 Oildyne =0A>actually sent me the spool and spring upgrade fr= ee of charge (no guarantee that =0A>would happen for everybody on the forum= !).=A0 With the new self centering spool =0A>and 3 way dump valve I am now = 100% confident I will not have a gear actuation =0A>failure - seen too many= u-tube videos of various types belly landing over a =0A>stupid hydraulic o= r electrical failure.=0A>=A0=0A>Tip:=A0 add pressure gauges to your system = if you have not already done so.=A0 You =0A>will learn a tonne about your s= ystem=0A>=A0=0A>Tom=0A>826Ct LNC2 360=0A>=0A>=0A>=0A_______________________= _________=0AFrom: Wolfgang =0A>To: lml@lancaironline.ne= t=0A>Sent: Sun, April 17, 2011 10:13:18 AM=0A>Subject: [LML] Gear operation= fix for the LNC2=0A>=0A>=0A>Here are some details on the Gear Fix Module -= - - - -=0A>=0A________________________________=0A=0A______________________= __________=0A=0A>There is a potential for the landing gear to fail to opera= te in the LNC2.=0A>=0A>The spool in the hydraulic pump can come off it's en= d position and seal the =0A>fluid volume in the lines. When the system incu= rs a large temperature rise, the =0A>trapped fluid expands raising the pres= sure in the lines, tripping both pressure =0A>switches open=A0and making th= e=A0hydraulic pump inoperable.=0A>=0A>A module to fix this gear operation f= ailure=A0in the LNC2 using the standard =0A>hydraulic system is now availab= le. It is installed across the pressure switches =0A>and monitors their ope= ration. If both switches are=A0tripped open by high =0A>pressure, the pump = is made to run in the direction set by the gear switch =0A>re-seating the s= pool in it's end position=A0restoring normal pump operation and =0A>relievi= ng pressure in the offending side. This happens automatically without =0A>p= ilot intervention.=0A>=0A>The module is=A02.5" x 1.5" x .75", weighs 2.3 oz= .=A0and has two pairs of leads that =0A>connect directly to each pressure s= witch with 1/4" spade terminals. No other =0A>wiring is necessary. Price is= $250.00 each. Simple installation instructions =0A>included.=0A>=0A>Contac= t Wolfgang Franke at 248-471-2000 or Wolfgang@MiCom.net=0A_________________= _______________=0A=0A>=0A________________________________=0A= =0A>=0A________________________________=0A=0A>=A0=0A>----- Or= iginal Message ----- =0A>>From: Bryan Wullner =0A>>To: lml@lancaironline.ne= t =0A>>Sent: Saturday, April 16, 2011 8:24 PM=0A>>Subject: Re: [LML] Re: LN= C2 Gear Hydraulics=0A>>=0A>>Wolfgang, =0A>>What is your gear fix module?=0A= >>Bryan=0A>>=0A>>=0A>>On Fri, Apr 15, 2011 at 10:11 AM, Wolfgang wrote:=0A>>=0A>>From a design point of view, I still have a big = concern about relying on the =0A>>friction from an O-ring to keep the landi= ng gear functioning properly. Vibration =0A>>levels can exceed 70 G's. I wo= uld be much happier with a spring loaded ball =0A>>detent or something simi= lar.=0A>>>=A0=0A>>>That's why I came up with the gear fix=A0module.=0A>>>= =A0Wolfgang=0A>>>=A0=0A>>>----- Original Message ----- =0A>>>>From: Chris Z= avatson =0A>>>>To: lml@lancaironline.net =0A>>>>Sent: Wednesday, April 13, = 2011 8:25 AM=0A>>>>Subject: Re: [LML] Re: LNC2 Gear Hydraulics=0A>>>>=0A>>>= >=0A>>>>A symmetric back-pressure circuit and spool will eliminate the poss= ibility of =0A>>>>installing the spool backwards as happened with pumps man= ufactured in about the =0A>>>>'96 through '98 time frame.=A0 The spool must= still remain in place after the pump =0A>>>>shuts down to prevent both hig= h and low circuits from locking up simultaneously.=0A>>>>Using o-ring=A0013= -70 requires 30 g's to move the spool.=0A>>>>Using o-ring=A0013-90 requires= 70 g's to move the spool.=0A>>>>This includes the return force generated b= y the poppet springs (410462).=A0 =0A>>>>The difference between the two o-r= ings is durometer.=A0 I have been using the =0A>>>>softer one without any p= roblems.=A0 The stiffer o-ring (intended for pumps with =0A>>>>back pressur= e circuits) should leave no doubt.=A0 The first thing to do with a =0A>>>>p= ump that has a history of locking up both sides is to measure the return fo= rce =0A>>>>for the spool and make sure it has an o-ring installed.=0A>>>>= =0A>>>>Chris Zavatson=0A>>>>N91CZ=0A>>>>360std=0A>>>>www.N91CZ.net=0A>>>>= =0A>>>>=0A>>>>=0A________________________________=0AFrom: Wolfgang =0A>>>>To: lml@lancaironline.net=0A>>>>Sent: Mon, April 11, 201= 1 4:56:57 AM=0A>>>>Subject: [LML] Re: LNC2 Gear Hydraulics=0A>>>>=0A>>>>=0A= >>>>When I first got into this problem with the hydraulic pumps last year, = I had a =0A>>>>few conversations with the product manager of the Oildyne 10= 8 pump. There have =0A>>>>been many changes in it's production life and one= of them was to make the spool =0A>>>>symmetrical and have the relief circu= it the same both ways.=0A>>>>=A0=0A>>>>Wolfgang=0A>>>>=0A__________________= ______________=0A=0A>>>>Wolfgang,=0A>>>>Yes, I have considered this. =A0The= spool with O-ring is a very tight fight. =0A>>>>=A0While I have not tried = to measure the force to move it, I would estimate =0A>>>>something over 50 = g's to move it (I'll measure this the next time I have a pump =0A>>>>opened= up) =A0Could it be that a pump somehow ended up mounted such that it was = =0A>>>>subjected to some resonant frequency? =A0Seems like a remote possibi= lty given all =0A>>>>the variables and the mass of the pump. =A0 =A0How abo= ut wear and tear?=A0=A0Perhaps =0A>>>>sitting dry and idle for ten years wo= uld do it. =A0A missing O-ring or a spool =0A>>>>that doesn't utilize an O-= ring would allow the spool to move very easily. =0A>>>>=A0Parker does make = spools that don't even have O-rings. =A0Did these end up getting =0A>>>>ins= talled by chance?=0A>>>>=0A>>>>=0A>>>>Based on reports from the LML, the be= havior seems to be rather binary. =A0On the =0A>>>>one hand we have planes = with over 1000 hours and more than ten years of service =0A>>>>that have ne= ver once had the spool move off the poppet. =A0On the other hand, we =0A>>>= >have planes with circuits that lock up right out of the box (put into serv= ice).=0A>>>>This leads me to believe there is a difference in configuration= . =A0The easiest =0A>>>>way to verify this is to simply open up a pump that= is known to lock up hi and =0A>>>>low circuits simultaneously.=0A>>>>=0A>>= >>=0A>>>>While I have opened up several pumps (primarily to flip around spo= ol valves), I =0A>>>>have not yet worked on one that had this lock up issue= . =A0I am optimistic the =0A>>>>difference will be quite obvious upon inspe= ction. =A0=0A>>>>=0A>>>>=0A>>>>Chris Zavatson=0A>>>>N91CZ=0A>>>>360std=0A>>= >>www.N91CZ.net=0A>>>>=0A>>>>=0A>>>>=0A>>>>Sent from my iPad=0A>>>>=0A>>>>O= n Apr 7, 2011, at 11:53 AM, "Wolfgang" wrote:=0A>>>>= =0A>>>>=0A>>>>Chris, have you considered what effect airframe vibration has= on the position of =0A>>>>the spool in the pump and the problem in general= ?=0A>>>>>=A0=0A>>>>>Wolfgang=0A>>>>>=0A________________________________=0A= =0A>>>>>From: Chris =0A>>>>>Sender: =0A>>>>>Subject: Re: [LML] Re: LNC2 Gear Hydraulics =0A>>>>>Da= te: Wed, 06 Apr 2011 07:38:35 -0400 =0A>>>>>To: lml@lancaironline.net =0A= >>>>>I would like to extend the offer to the whole group. =A0I think the en= tire =0A>>>>>community would benefit from understanding why some pumps are = allowing the =0A>>>>>system to lock up. =A0If anyone has a pump that exhibi= ts this behavior and could =0A>>>>>part with it for a week, I am willing to= check it out on the test stand and =0A>>>>>examine the internal configurat= ion.=0A>>>>>=0A>>>>>=0A>>>>>Chris Zavatson=0A>>>>>N91CZ=0A>>>>>360std=0A>>>= >>www.N91CZ.net =0A>> --0-1550552429-1303185503=:1655 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Chris,
=0A
 
=0A
You are right, looking at = the drawing from Oildyne (I posted some time back) I agree that the low pre= ssure poppet needs to remain open and it does so since the pressurized side= keeps the spool forced up against the poppet by overcomming the spring for= ce.  If the high side leaks to zero then the spool will center but onl= y then.  So it could be argued why bother with the extra springs at al= l.  Oildyne's response to that was that it prevents sticking of the sp= ool.  I might reconsider and remove the springs if I notice the system= missbehaving, so far it has not,.  My fallback right now is the three= way dump valve. 
=0A
 
=0A
What took me here = in the first place was  that I was getting pressurization on the low s= ide that was either due to a bad bypass valve, expansion or leakage across = the spool, which was not cracking the relief valve (I subsequently rem= oved that valve which allows all fluid to vent to the tank immediatly on th= e low side) There is no need for this valve since the low side is not provi= ding a retaining function
=0A
 
=0A
Tom
=0A=
=0A
=0A
=0AFrom: Chris <chris_zavatson@yahoo.co= m>
To: lml@lancaironl= ine.net
Sent: Mon, April= 18, 2011 8:56:21 PM
Subject: [LML] Re: Gear operation fix for the LNC2

=0A
Tom,<= /DIV>=0A
Please be carefull with system changes.  I still sounds l= ike you have designed in the very condition we seek to avoid.  The spo= ol must keep the poppet valve open else you seal off the side that needs to= remain at zero pressure.  Wolfgang's circuit will undo this undesirab= le condition once the "zero side" has been pressurized enough to close the = pressure switch.  Until then however, the net working pressure of the = system is reduced (net=3Dhigher side pressure minus lower side pressure). &= nbsp;It also adds wear and tear by requiring additional pump cycles to rest= ore the unlocked condition.  Best to keep the spool where it was last = commanded, the way the pump was designed to do.  The symmetric spool a= voids installation errors - a good thing (I would really like to examine sc= hematics and drawings to look for any unintended consequences).  Press= ure gauges should be considered a must-have.
If your pump now has some n= ew way of keeping the non-working side from becoming pressurized, please elab= orate.  In all seriousness, we just want to make sure you don't end up= in one of those you-tube videos.
=0A

=0A
Chris Zava= tson
=0A
N91CZ
=0A
360std
=0A=0A
Sent from my iPad
=0A

On Apr 18, 2011, at 9:09 AM, TOM = GARDINER <n20087@yahoo.com> wrote:
=0A
=0A
=0A
=0A
=0A
=0A<= P class=3DMsoNormal style=3D"MARGIN: 0in 0in 0pt">Folks,

=0A

 

=0A

As I posted some time back, there is a fix for the spool g= etting stuck in one position or the other.  Oildyne offers additional = springs and a symmetric spool (not the original symmetric spool)  The = alternative spool is ported on both sides to allow fluid to move freely to = tank when pushing excess blind end fluid back to tank.  (The other sid= e being ported does not really matter)  The springs which are quite he= avy will certainly center the spool and take it off the poppets and bypass = relief valve after the pump is de-energized.  Oildyne actually sent me= the spool and spring upgrade free of charge (no guarantee that would happe= n for everybody on the forum!).  With the new self centering spool and= 3 way dump valve I am now 100% confident I will not have a gear actuation = failure - seen too many u-tube videos of various types belly landing over a stupid hydraulic or electrical failure.=

=0A

 

=0A=

Tip:  add pressure gauges to = your system if you have not already done so.  You will learn a tonne a= bout your system

=0A

 

=0A

Tom

=0A<= P class=3DMsoNormal style=3D"MARGIN: 0in 0in 0pt">826Ct LNC2 360

=0A<= DIV style=3D"FONT-SIZE: 8pt; FONT-FAMILY: arial, helvetica, sans-serif">=0A
=0A
=0AFrom: Wolfgang <Wolfgang@MiCom.net>
To: lml@lancaironline.net
Sent: Sun, April 17, 2011 10:13:18 AM
Subject: [LML] Gear operation fix fo= r the LNC2

=0A=0A=0A
Here are some details on the Gear Fix Module - - - - -
= =0A
=0A
=0A=0A
=0A
=0A
There= is a potential for the landing gear to fail to operate in the LNC2.=
=0A
 
=0A
The spool in = the hydraulic pump can come off it's end position and seal the fluid volume= in the lines. When the system incurs a large temperature rise, the trapped= fluid expands raising the pressure in the lines, tripping both pressure sw= itches open and making the hydraulic pump inoperable.=0A
 
=0A
A module to fix th= is gear operation failure in the LNC2 using the standard hydraulic sys= tem is now available. It is installed across the pressure switches and moni= tors their operation. If both switches are tripped open by high pressu= re, the pump is made to run in the direction set by the gear switch re-seat= ing the spool in it's end position restoring normal pump operation and= relieving pressure in the offending side. This happens automatically witho= ut pilot intervention.
=0A
 
=0A
The module is 2.5" x 1.5" x .75", weighs 2.3 oz.&nbs= p;and has two pairs of leads that connect directly to each pressure switch = with 1/4" spade terminals. No other wiring is necessary. Price is $250.00 e= ach. Simple installation instructions included.
=0A
 <= /DIV>=0A
Contact Wolfgang Franke at 248-471= -2000 or Wo= lfgang@MiCom.net
=0A

=0A
=0A=0A

=0A<GearFix2s.jpg>=0A

=0A
=0A=0A

=0A
&= lt;GearSw1s.jpg>
=0A

=0A
=0A=0A
=0A
 = ;
=0A
=0A
----- Original Message ----- =
=0A
From: = Bryan Wullner =0A=0A
= Sent: Saturday, April 16, 2011 8:24 PM
=0A
Subject: Re: [LML] Re: LNC2 Gear Hydraulics
=0A
=
Wolfgang, =0A
What is your gear fix module?
=0A
Brya= n

=0A
On Fri, Apr 15, 2011 at 10:11 AM, Wolf= gang <Wolfgang@micom.net> wrote:
=0A=0A
=0A
= From a design point of view, I still have a big concern about relying on th= e friction from an O-ring to keep the landing gear functioning properly. Vi= bration levels can exceed 70 G's. I would be much happier with a spring loa= ded ball detent or something similar.
=0A
 
=0A
That's wh= y I came up with the gear fix module.
=0A
 
=0A
Wolfgang
=0A
 
=0A
=0A
=0A
-= ---- Original Message -----
=0A
=0A
=0A
=0A
=0A=0A
Sent: Wednesday, April 13, 2011 8:25 AM=0A
Subject: Re: [LML] Re: LNC2 G= ear Hydraulics
=0A

=0A
=0A
A symmetric back-pressure c= ircuit and spool will eliminate the possibility of installing the spool bac= kwards as happened with pumps manufactured in about the '96 through '98 tim= e frame.  The spool must still remain in place after the pump shuts do= wn to prevent both high and low circuits from locking up simultaneously.=0A
Using o-ring 013-70 requires 30 g's to move the spool.=0A
Using o-ring 013-90 requires 70 g's to move the spool.
Thi= s includes the return force generated by the poppet springs (410462). =
=0A
The difference between the two o-rings is durometer.  I= have been using the softer one without any problems.  The stiffer o-r= ing (intended for pumps with back pressure circuits) should leave no doubt.=   The first thing to do with a pump that has a history of locking up b= oth sides is to measure the return force for the spool and make sure it has= an o-ring installed.
=0A
 
=0A
Chris Zavatson
= =0A
N91CZ
=0A
360std
=0A=0A

=0A
= =0A
=0AFrom: Wolfgang <Wol= fgang@MiCom.net>
To:<= /B> lml@lancaironline.net
= Sent: Mon, April 11, 2011 4:56:57 AM
Subject: [LML] Re: LNC2 Gear Hydraulics
<= BR>=0A
When I first got into this problem w= ith the hydraulic pumps last year, I had a few conversations with the produ= ct manager of the Oildyne 108 pump. There have been many changes in it's pr= oduction life and one of them was to make the spool symmetrical and have th= e relief circuit the same both ways.
=0A
 
=0A
Wolfgang
=0A
=0A
=0A
=0A=0A
=0A
Wolfgang,
=0A
Yes, I have considered this. &nbs= p;The spool with O-ring is a very tight fight.  While I have not tried= to measure the force to move it, I would estimate something over 50 g's to= move it (I'll measure this the next time I have a pump opened up)  Co= uld it be that a pump somehow ended up mounted such that it was subjected t= o some resonant frequency?  Seems like a remote possibilty given all t= he variables and the mass of the pump.    How about wear and tear= ?  Perhaps sitting dry and idle for ten years = would do it.  A missing O-ring or a spool that doesn't utilize an O-ri= ng would allow the spool to move very easily.  Parker does make spools= that don't even have O-rings.  Did these end up getting installed by = chance?
=0A

=0A
Based on r= eports from the LML, the behavior seems to be rather binary.  On the o= ne hand we have planes with over 1000 hours and more than ten years of serv= ice that have never once had the spool move off the poppet.  On the ot= her hand, we have planes with circuits that lock up right out of the box (p= ut into service).
=0A
This leads me to believe there = is a difference in configuration.  The easiest way to verify this is t= o simply open up a pump that is known to lock up hi and low circuits simult= aneously.
=0A

=0A
While I have opened up seve= ral pumps (primarily to flip around spool valves), I have not yet worked on= one that had this lock up issue.  I am optimistic the difference will= be quite obvious upon inspection.  
=0A

=0A
Ch= ris Zavatson
=0A
N91CZ
=0A
360std
=0A=0A
<= FONT face=3DArial size=3D2>
=0A

Sent from my iPad=0A

On Apr 7, 2011, at 11:53 AM, "Wolfgang" <Wolfgang@MiCom.net>= ; wrote:

=0A
=0A
=0A
= =0A
Chris, have you considered what effect = airframe vibration has on the position of the spool in the pump and the pro= blem in general ?
=0A
&n= bsp;
=0A
Wolfgang
=0A
= =0A
=0A
=0A
=0A=0A=0A=0A=0A
=0A=0A=0A= =0A=0A
=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A=0A
From:Chris= <chris_zavatson@yahoo.com>=
Sender:<marv@lan= caironline.net>
Subject:Re: [= LML] Re: LNC2 Gear Hydraulics
Date:Wed, = 06 Apr 2011 07:38:35 -0400
To:<= A href=3D"mailto:lml@lancaironline.net" target=3D_blank rel=3Dnofollow ymai= lto=3D"mailto:lml@lancaironline.net">= lml@lancaironline.net
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I would like to extend the offer to t= he whole group.  I think the entire community would benefit from under= standing why some pumps are allowing the system to lock up.  If anyone= has a pump that exhibits this behavior and could part with it for a week, = I am willing to check it out on the test stand and examine the internal con= figuration.
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=0A
Chris Zavatson
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N91C= Z
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360std
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=
<= /DIV>
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