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hydro101

Rudder squeal

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Need some help with a problem. Ran flaps to 15% stopped for a sec then ran it to 0%. Got a very loud squeal only does it when ever it wants to. changed out diverter valve press reducer rudder boost pack check valve. Checked electrics and line vibrations. It comes and goes we can run for a hour and it wont happen but then you run for 15 min and it cant stop. Also bled lines of air. WTF :confused: Any help would be great

Edited by hydro101

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Is the noise coming from the rudder boost pack or the diverter valves? If it is coming from the diverter panel is it the Booster or Utility side? You sure it isn't the elevator boost pack bypassing? They will squeal sometimes...normal operation if it is. The best way to make sure is have someone pull back on the yoke and see if the noise goes away or changes.

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It is the booster side diverter panel. I know what you are saying about the elev pack but you can hear it squeal from the flight deck with headphones on and engines running. rudder pack and elev pack are out of the question.

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I have experienced this problem a few times. Each time, it has been the pressure reducer itself causing the problem. When I first ran into it, it was intermittent. When we ignored it, it finally caused broken Adell clamps on the hydraulic lines and eventually cracked pressure lines where it dumped the hydraulic systems.

Keep in mind that sound travels through metal and will seem to come from somewhere other than the original source. If you haven't tried it, and you can get the squeal to be continuous, use your hand on the individual components to help you find the noise.

Also, we have discovered that not all new parts nor all repaired parts are actually good parts.

I wish you luck with this one.

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I have experienced this problem a few times. Each time, it has been the pressure reducer itself causing the problem. When I first ran into it, it was intermittent. When we ignored it, it finally caused broken Adell clamps on the hydraulic lines and eventually cracked pressure lines where it dumped the hydraulic systems.

Keep in mind that sound travels through metal and will seem to come from somewhere other than the original source. If you haven't tried it, and you can get the squeal to be continuous, use your hand on the individual components to help you find the noise.

Also, we have discovered that not all new parts nor all repaired parts are actually good parts.

I wish you luck with this one.

Well we canned the reducer 3 times got a new one and did the same thing. Took out the whole panel and swapped it with another. I know what you are saying about the vibrations. I help my flashlight on the shutoff valve and it was going crazy. Vibrating hard enought to turn my flashlight off. So I shot the wires for voltage/amps/and ohms. Both booster and utl side match on point. We are submitting a 107 to have someone come out here. Feel bad though. Tried to fix it but these planes do weird things.

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Has there been any hydraulic fittings replaced on the panel? After everything you mentioned. I would look at the hydraulic fittings, especially elbows or anything that abrubtly changes the flow of fluid. There could be a machine bur or damage that would cause a fitting or line to vibrate. I would look at the connections to the diverter panel for damage or obstructions. Without seeing firsthand, that one is going to be a fun one to troubleshoot.

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With the flaps between 0 and 15% (while you have the squeal) have you selected the boost shutoff valve to OFF to stop the flow of fluid to the diverter panel? Did the squeal stop?

I assume you have due to the replacement of the diverter valve and other repairs.

But your initial post says

"It comes and goes we can run for a hour and it wont happen but then you run for 15 min and it cant stop."

Just wondering...

Edited by NATOPS1

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Here is what we did. 1st ran system as normal. From 15% to 0% flaps squealed. Took cannon plug off of shut off valve and still made noise.Valve is denergized open and energized closed. Next took cannon plug off diverter valve still made noise. All are new parts on the panel. Next bled system the non perfered way by just cracking b-nuts and draining into a bucket still squeels. Shot wires ohms amps and volts are good. Thinking mabe the shut off valve was getting stray voltage and semi closing it. I know this is bad but I used a test light to check for amps. No you arent suppose to use it but hey got to use what I got. So at this point I got the reps looking at it and they are confused also. I want to change the shut off valve but when I ran a jumper wire from the utl side it still squealed!!!!!!!!!!!!!!!!!!! Man 130's have weird things happen to them. Oh and sorry about talking trash on other posts

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Does the noise happen at all flap settings or just 0-15%?

"Took cannon plug off of shut off valve and still made noise."

(I would have expected the same result)

Unless the Boost shutoff switch is placed in the OFF position there is no power to "close" the (solenoid) valve.

I understand based on your post you thought the valve may have been cycling and wanted to check.

Now, ensure the shutoff valve works.

Only run the effected (Booster) hydraulic system and if the noise is present place the Boost shutoff switch to the OFF position. See if the valve closes (it will be very hard to move the rudder) (NO BOOST)

Also note if your noise stops.

If the noise stops it (noise) is coming from the section downstream of the shutoff valve, diverter panel, Pressure transmitter, Filter (Filter bypass) or Boost unit itself. (Does the rudder move as directed? Control valve not recenter)

If the noise continues and the shutoff valve is verified closed (very hard to move the rudder) it is coming from upstream (prior to) the shutoff valve.

"Next took cannon plug off diverter valve still made noise."

(I would have expected the same result)

0-15% no power flows to the diverter valve (it is deenergized (flaps up) high speed configuration) (If this was cycling you would see pressure flux on your cockpit instruments)

(If you move the flaps 16-100% does the noise stop?)

"Shot wires ohms amps and volts are good"(that’s some good news)

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Have you checked/replaced the pressure relief valve? If the relief valve didn't reseat itself right it could be the culprit.

Keep digging and good luck.

Sonny

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hydro101- haha that rudder was a pain in the butt!!! But hey we had some good times troubleshooting! Learning how to shoot wires from a hydro troop = priceless

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We had the same problem a couple of years ago. On an E that was being upgraded. If it sounds like a damn whale in the cargo compartment when you move the rudder, or move the rudder and run some flap, or do some other odd combo of flight controls then it is the same problem. I agree it can get REALLY loud. The problem is in the diverter panel. Had an old time designe engineer come up from Marietta. Our panel needed another piece of plumbing, essentially adding a bit of a run-around plumbing to the panel. I'll see if I can dig up the EA for you. Fixed it 100 percent.

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Since there is no fix posted I figured I would chime in here.

We had the same problem about a month ago on an Canadian E model, we replaced the pressure reducer and it did not fix the snag. Our fix was simply replacing the Utility side filter element on the pack itself. Reason why we changed the utility filter was because the noise was happening only when the boost side of the system was cut-off. And the noise seemed that it was coming from the pack, and not the lines or valves.

The filter fixed the problem because the pack was stuck in by-pass mode. I figured that since the pack has no pop-its there had to be a way the pack would indicate a blocked filter, I guess the noise was its indication.

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