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jan.mevis(at)informavia.b
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 Posted: Fri Aug 28, 2015 11:47 pm Post subject: Sticky valve? |
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I'd be very cautious too.
I follow the Russian advise: a small quantity of a 50/50 mixture op pure
ethanol (96 degrees) and high-quality glycerine.
My Lithuanian mechanic injects a small quantity (only a few cubic
centimeters) of this stuff straight into the actuators annually.
Of course it'll depend upon the material that you use for the seals at
overhaul. I have the gear legs and actuators overhauled in Lithuania at
Termikas.
And therefore I trust their advise.
Otherwise I'd do exactly the same as Mark: no stuff at all, if you don't
know what is inside.
At the beginning I was suspicious about the use of ethanol since it
attacks natural rubbers.
But the Russian inspector explained the reasoning behind: the ethanol
binds the moisture and the glycerine keeps the seals in shape.
Jan
On 28/08/15 22:51, "Bitterlich, Mark G CIV NAVAIR, WD"
<owner-yak-list-server(at)matronics.com on behalf of
mark.bitterlich(at)navy.mil> wrote:
[quote]
<mark.bitterlich(at)navy.mil>
I was talked into putting pneumatic tool oil into my pneumatic system
back around 2001 or so, on the original version of the YAK LIST.
I had just purchased my YAK-50 and had no idea how old the landing gear
actuator seals were, but they were working fine at the time. I injected
the oil and several flights later, the seals in the landing gear
actuators started coming apart. What I noticed was air leaking out the
gear handle when the gear was down and locked. Luckily I figured out
that if the actuator had internal leakage, you would hear that at the
gear handle. When I took the actuators apart, the chevron seals were
pretty much like soft putty.
Granted, these were probably original Russian seals. Granted, they were
probably hardened and in very poor shape. However, the oil caused them
to just fall apart.
To each his or her own, but after that little experience I have never
injected a DARN thing into my air system. NADA ZERO ZIPPO. I did
rebuild the actuators, and honestly it is about time to do them again and
personally... I believe that rebuilding the actuators, and taking apart
and looking at pneumatic components every so often is a very good idea,
especially the areas where there is known corrosion issues and doing that
is much more important than injecting ANYTHING into that system.
As I said, I own a YAK-50, so my experience may not be applicable to 52's
or CJ's. However, I'd be very cautious of what I inject into the air
system and would not ad hoc it under any circumstance, or make guesses.
Also of note is that my brake system is no longer pneumatic, it is now
toe brakes and hydraulic. So my pneumatic system is just for landing
gear and starting.
There is long term impact with this decision, so caution is the order of
the day (so to speak).
Best of luck,
Mark
--
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Viperdoc
Joined: 19 Apr 2014
Posts: 484
Location: 08A
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| Posted: Sat Aug 29, 2015 5:50 pm Post subject: Sticky valve? |
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Your YAK 50 experience is applicable.
Doc
[quote] On Aug 28, 2015, at 3:51 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:
I was talked into putting pneumatic tool oil into my pneumatic system back around 2001 or so, on the original version of the YAK LIST.
I had just purchased my YAK-50 and had no idea how old the landing gear actuator seals were, but they were working fine at the time. I injected the oil and several flights later, the seals in the landing gear actuators started coming apart. What I noticed was air leaking out the gear handle when the gear was down and locked. Luckily I figured out that if the actuator had internal leakage, you would hear that at the gear handle. When I took the actuators apart, the chevron seals were pretty much like soft putty.
Granted, these were probably original Russian seals. Granted, they were probably hardened and in very poor shape. However, the oil caused them to just fall apart.
To each his or her own, but after that little experience I have never injected a DARN thing into my air system. NADA ZERO ZIPPO. I did rebuild the actuators, and honestly it is about time to do them again and personally... I believe that rebuilding the actuators, and taking apart and looking at pneumatic components every so often is a very good idea, especially the areas where there is known corrosion issues and doing that is much more important than injecting ANYTHING into that system.
As I said, I own a YAK-50, so my experience may not be applicable to 52's or CJ's. However, I'd be very cautious of what I inject into the air system and would not ad hoc it under any circumstance, or make guesses. Also of note is that my brake system is no longer pneumatic, it is now toe brakes and hydraulic. So my pneumatic system is just for landing gear and starting.
There is long term impact with this decision, so caution is the order of the day (so to speak).
Best of luck,
Mark
--
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Viperdoc |
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JL2A
Joined: 07 Apr 2015
Posts: 113
Location: Australia
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| Posted: Mon Aug 31, 2015 4:09 am Post subject: Re: Sticky valve? |
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so does anyone know what 'Number 8 Aviation Lubrication Oil' is, as per the CJ Maintenance Manual?
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