Main rotor trans fluid leak?
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Grant
Member Since : 2007
Posts(687)
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Main rotor trans fluid leak?

12-13-2011 04:50:35

Took a flight last night and noticed a stream of blue trans fluid coming from small hole near fuel strainer behind left rear doors. I noticed a vibration in the helicopter I never noticed before. landed and checked the little hole and more fluid streamed on side of ship. Any Ideas? The sight glass is normal level all teletemps normal and I dont understand what it could be to happen all of the sudden like this.  Ship is at 40 hour mark on way to next 50 service. Total ship time is 750tt.
Any help would be appreciated.

Replies

simon
Member Since : 2007
Posts(321)
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12-13-2011 06:12:24
I also have a small leak, that produces a smelly blue fluid. I believe it is from the main transmission and accumulates on the metal pan imiediatly behind the back seats. It is hard to clean up because it is hard to reach and there are quite a few moving parts and stiffeners in the way.
What I do know is when some accumulates and seeps into the cabin, it smells bad and is harder to clean up.
Definatly blue color, where does it come from?
Rossco
Member Since : 2010
Posts(41)
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12-13-2011 11:33:59
that blue fluid is AVGAS. If you have bladders it could be that you have a leak on the seal for the tank sender unit. My ship was 100 hrs when this happened. It starts out with a blue fluid that will hurt the paint if you let it stand for a while. Avgas leaks onto the pan and evaporates leaving a thick blue tacky fluid that resembles blue oil. I would bet 100 bucks that is your problem. Do you have bladders?
Rossco
Member Since : 2010
Posts(41)
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12-13-2011 11:37:29
this is a picture of underneath my main tank. The blue fluid is visible and leaked out the small hole at the rear left seat. It stained my paint and accummulated on the door frame and under the belly of the ship...
IMG_0497.JPG
No One
Member Since : 2018
Posts(232)
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12-13-2011 11:56:41
I fly an R44 II with a main gear box oil "leak, drip, seep", in any case it is minimal, and accumulates over time at the seam of the bottom sheet metal and fire wall.  If I let it go long enough it will pool and drain out of the small hole near the left fuel sump.  Mine looks like it originates from the lower plug and has a V spread pattern on the lower pan widening to the aircraft's left side, most likely do to airflow within the compartment.  About every 5 hours of flight I take a paper towel and wipe up any standing oil.  I have been told by mechanics that: ?some leak, just watch for any change in volume.?, also ?some gearboxes develop a crack on the backside (aircraft left).  Just watch to see if it gets worse.?  I've also been told the O rings in these things stink.  In any case I have it checked every 100hr inspection.  I even used an inspection mirror and can?t see any oil trails on the far side of the box.  My next action is to remove the mast and upper covers in an effort to view from the top.  I have never had to fill between 100hr inspections and it only seems to occur during and post operation while warm, it is not a constant leak.  Good luck
Chopperpilotgod
Member Since : 2015
Posts(3)
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12-14-2011 12:16:02
Well, Talked to the mechanics today...the pan does accumulate some main trans oil...when enough is on the pan it does seap out the vent hole near fuel sump behind left rear door. Main point is level in window is normal and doesnt move. I damn near had a hear attack when I saw that. Freaked me out. I was heavy last night with three and full tanks in philly class B. Love this helicopter and actually I am glad its nothing major.
Now...whats up with the chug? I was heavy last night and usually half the time I fly I am heavy....never felt a chug. Can anyone explain why I dont???
Chopperpilotgod
Member Since : 2015
Posts(3)
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12-14-2011 12:24:12
Sorry, No...I dont have bladders. I have a 2001 model and I hope it goes all the way without them. I did just do a clutch overhaul 20 hours ago. That was a return and rebuild at Robinson factory. My mechanics are big time Robinson guys...Personal friends with frank. I called them this morning and an hour later they were on it. Problems checked and serviced. I always feel better when They put an eye on it.
Rossco
Member Since : 2010
Posts(41)
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12-14-2011 11:00:50
who are your mechanics in the Philly area. Im in Jersey and looking
simon
Member Since : 2007
Posts(321)
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12-15-2011 12:47:18
Mine is a 2001 as well. Raven 1
Is there any othe guilds except avgas that is blue?
simon
Member Since : 2007
Posts(321)
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12-15-2011 05:45:01
Should say, "any other fluids"

Darn spellcheck
nskaye
Member Since : 2007
Posts(89)
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12-15-2011 07:46:03
I'm in Wilmington/Newark, Delaware and Jim is the mechanic at Horizon Helicopters.  He's R44 factory trained and has always kept my ships in perfect shape.  Not far from Philadelphia at all.  Call him at 302-368-5135 if you need work done.  He does Jets, 500's, Enstroms, etc. also.

Neil