Hey, thanks for your response.

Which flight date are you looking at?

Your test gauge offer is much appreciated, does it monitor both HI and LO sides or do you switch from one side to the other?

I put 4ZQ up on jacks this morning and raised the gear. HI pressure immediately started to bleed off but it was interesting to note

that the gear stayed tucked up nicely until the pressure had dropped to 310psi. At this pressure, the gear doors had begun to open by about .125”.



Angier Ames



I’m at 250 Cutler Road

South Hamilton, MA. 01982





On Aug 7, 2014, at 8:08 PM, John Cooper <snopercod [at] comporium.net> wrote:



> Angier--

>

> I'm no "wizard", but In looking at that data, everything seemed to be just fine until 9:31:45 when the LO pressure spiked up to 1220 and then bled off. A few seconds later, at 9:31:54, apparently you put the gear up since the high pressure went up to 1490 then started a slow decay for 17 minutes until 9:49:12, Whatever happened, it got worse from then on. Maybe you can relate those times to anything you might have been doing at those times?

>

> I don't think it matters, though; I'm guessing you have an internal leak somewhere. OTOH, The high-pressure switch kept starting the pump at ~850 (sounds right to me)  and shutting it off at ~1050 (seems a little low). So the pressure switch was doing its job.

>

> What happened between 10:58:26 and 10:58:32 when there was little pressure on either side? Was the dump valve open for 6 seconds or was that just a transition from Gear Down to Gear Up? If the latter, it seems kind of long...

>

> I'm assuming that your pump is the newer model with the back pressure circuit?

>

> Bottom line: If I were in your situation, I would isolate the pump and check the pressures. I'd be glad to mail you my test gauge if you'd like.

>

> Best--

>

> --John

>

Angier,

It looks like it is time to start isolating circuits and then actuators.  If it is a cylinder, don't forget about the sealing washer under the piston nut.

Chris



Sent from my spiffy iPhone



On Aug 7, 2014, at 4:07 PM, "Greenbacks, UnLtd." <n4zq [at] verizon.net> wrote:



> Hey guys, I have attached an excel spreadsheet showing the hydraulic pressure data for nine flights from March 5, 2013 through August 6, 2014.

> The data for the first 6 flights seem fairly typical, and I would expect minor changes due to altitude/temperature differences.

> The flight on July 11th for example had the gear coming up at 7:21:12am with the pump shutting off at 1440psi. and slowly dropping to 1080psi at 7500ft

> where Bill Harrelson aka Wineaux and I conducted a first GAMI lean exercise. Not sure why some residual pressure seems to remain on the low side.

> Perhaps one of you can shed light on this.

> The first indication of any irregularity occurred on the 7/31 flight at 9:49:09am when the pressure had dropped to 850 and the pump came on. The on cycles were momentary

> for the remainder of the flight but came with greater frequency.

> For the last flight on 8/6, the gear came up with the pump shutting off at 1470psi and I climbed to 2500ft, pressure immediately began to drop and the pump cycled again at 860psi

> and the recycle events came with greater frequency.

>

> So at this point, there is no evidence of any external fluid leaks. I’m thinking there may an internal leak in one of the six actuators, an issue with the pump itself, or possibly….

> a failing high pressure limit switch.

>

> Any comments and advice from all you hydraulic wizards is gratefully appreciated.

>

> Thanks,

>

> Angier Ames

> N4ZQlml

>

> This file only contains the last three flights due to the size of the original not being accepted on LML.

> The complete file is posted to Lancairtalk.net.

>

> <new data.xlsx>

> --

> For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

and as the high pressure begins to drop, should we not see a corresponding
increase in pressure on the low side?

Hi Chris,


You said.."It looks like it is time to start isolating circuits and then actuators.  Agreed


I’m not sure what you mean by this.

If it is a cylinder, don't forget about the sealing washer under the piston nut.”

OK, hear’s a dumb question for you….

I have no external leaks so, if there is an internal leak in one of the actuators(I mean cylinders for gear and doors, , and as the high pressure begins to drop, should we not see a corresponding
increase in pressure on the low side?

As for the dump valve, I trashed that which came with the kit in favor of higher quality. I don’t think I have a dump valve issue.

Hoping this does not screw up my plans for KRDM.


Angier
N4ZQ




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