I have a sticky main strut in my Pa-28-151. My engineer has suggested
changing the o-rings and valves of both struts. I was curious about the
whole structure and have looked everywhere in the internet with no luck Any
suggestions where I could find them?

Gus

Apologies, I ";looked everywhere in the internet for diagrams, with no luck"


Gus
"Gus Cabre" > wrote in message
...
>I have a sticky main strut in my Pa-28-151. My engineer has suggested
>changing the o-rings and valves of both struts. I was curious about the
>whole structure and have looked everywhere in the internet with no luck Any
>suggestions where I could find them?
>
> Gus
>
>

On Feb 10, 12:13 pm, "Gus Cabre" > wrote:
> Apologies, I ";looked everywhere in the internet for diagrams, with no luck"
>
> Gus"Gus Cabre" > wrote in message
>
> ...
>
> >I have a sticky main strut in my Pa-28-151. My engineer has suggested
> >changing the o-rings and valves of both struts. I was curious about the
> >whole structure and have looked everywhere in the internet with no luck Any
> >suggestions where I could find them?
>
> > Gus

Gus: I have an exploded diagram of the mains in my warrior parts
catalog if that is what you are looking for. If you don't turn one up
send me your email and I'll zap a scanned copy to you. Leo

>I have a sticky main strut in my Pa-28-151.

Where do you live?

If it's in a cold weather climate, having sticky main gear struts on a
Cherokee is NORMAL at this time of year.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:
>> I have a sticky main strut in my Pa-28-151.
>
>
> Where do you live?
>
> If it's in a cold weather climate, having sticky main gear struts on a
> Cherokee is NORMAL at this time of year.

They stick a lot less if you fly it frequently (at least once a week),
and keep the struts free of dirt. if you do have it rebuilt, have the
A&P check to make sure the strut bushing isn't worn so that the strut
gets cocked slightly, jamming it position. If it is, the only solution
is to replace the strut bushings that the strut rides in.

>> If it's in a cold weather climate, having sticky main gear struts on a
>> Cherokee is NORMAL at this time of year.
>
> They stick a lot less if you fly it frequently (at least once a week), and
> keep the struts free of dirt. if you do have it rebuilt, have the A&P
> check to make sure the strut bushing isn't worn so that the strut gets
> cocked slightly, jamming it position. If it is, the only solution is to
> replace the strut bushings that the strut rides in.

The last few flights, with the temperature near zero, our left strut stuck
up after landing, only compressing back down when we made the right turn
onto the taxiway, forcing it down with some centrifugal force.

At these temperatures NOTHING moves easily. The yoke moves hard, the flaps
don't retract, the knobs on the radios turn stiffly... You should hear the
noises coming out of my truck.

Hard to believe last Valentine's Day we had to scrub some of our "romantic
sunset flights" because it was *raining* all the time. This year, liquid
water is only possible indoors...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On 2008-02-12, Jay Honeck > wrote:
> At these temperatures NOTHING moves easily. The yoke moves hard, the flaps
> don't retract, the knobs on the radios turn stiffly... You should hear the
> noises coming out of my truck.

The first time I took my shiny new Lexus out in subzero weather, I thought
something was broke. It *never* made that kind of noise before.

I'm already planning on how to seal up the air leaks in whatever I wind up
buying so the cabin heat has a chance to keep up.
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
http://www.hercules-390.org (Yes, that's me!)
Buy Hercules stuff at http://www.cafepress.com/hercules-390

Gus Cabre wrote:
> I have a sticky main strut in my Pa-28-151. My engineer has suggested
> changing the o-rings and valves of both struts. I was curious about the
> whole structure and have looked everywhere in the internet with no luck Any
> suggestions where I could find them?
>
> Gus
>
>
As others have said, these things sticking is fairly normal. You
generally don't rebuild them until they start to leak. Since they
already leak somewhat, you just wait until the amount becomes a bit
messy and/or servicing them with air (or nitrogen as some prefer) gets
to be a chore.

I was surprised to find they stuck about the same after rebuilding all
of them as they did before.

If one is really sticking way more than the other you might be tempted
to change them both. But their "stickiness" will vary quite a bit from
strut to strut depending on the temperature and how much bouncing around
the bird gets when parked on the ramp for weeks at a time.

You may want to invest in a service manual and parts manual. Both are
now available on CD-ROM. It helps to have these to review before (or
after) you discuss matters with you mechanic. Just remember that the
mechanic has the benefit of actually DOING these operations, often many
times. They can tell you when the chapter and verse in the book ain't
quite how it REALLY happens.

Good Luck,
Mike

I routinely put both forearms under the center of each wing tip and lift to
unstick the main struts before each flight. I also do a little bounce on
the step to pull up the nose strut before boarding. It just seems to be a
normal part of owning a Cherokee.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel


"Jay Honeck" > wrote in message
news:NV6sj.29495$9j6.24433@attbi_s22...
>>> If it's in a cold weather climate, having sticky main gear struts on a
>>> Cherokee is NORMAL at this time of year.
>>
>> They stick a lot less if you fly it frequently (at least once a week),
>> and keep the struts free of dirt. if you do have it rebuilt, have the
>> A&P check to make sure the strut bushing isn't worn so that the strut
>> gets cocked slightly, jamming it position. If it is, the only solution
>> is to replace the strut bushings that the strut rides in.
>
> The last few flights, with the temperature near zero, our left strut stuck
> up after landing, only compressing back down when we made the right turn
> onto the taxiway, forcing it down with some centrifugal force.
>
> At these temperatures NOTHING moves easily. The yoke moves hard, the
> flaps don't retract, the knobs on the radios turn stiffly... You should
> hear the noises coming out of my truck.
>
> Hard to believe last Valentine's Day we had to scrub some of our "romantic
> sunset flights" because it was *raining* all the time. This year, liquid
> water is only possible indoors...
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"

You could try brushing some STP on the outside of the exposed strut.
It is amazing how a tiny amount of STP will reduce elastomeric seal
friction for many cycles, but it will probably have to be replaced
(rebrushed) every few weeks. From my experience in hydraulics, it
would cut friction easily in half for many cycles.

nrp wrote:

> You could try brushing some STP on the outside of the exposed strut.
> It is amazing how a tiny amount of STP will reduce elastomeric seal
> friction for many cycles, but it will probably have to be replaced
> (rebrushed) every few weeks. From my experience in hydraulics, it
> would cut friction easily in half for many cycles.

Good idea. Better yet, add a little STP to the hydraulic oil next time
the strut is overhauled. Dry graphite powder works, as well.

Happy Flying!
Scott Skylane

"Gus Cabre" > wrote in message
...
>I have a sticky main strut in my Pa-28-151. My engineer has suggested
>changing the o-rings and valves of both struts. I was curious about the
>whole structure and have looked everywhere in the internet with no luck Any
>suggestions where I could find them?
>
> Gus
>

Dear All,

Thanks for the replies.

Jay, I live in England and this winter is turning out to be quite warmish.
So it's not the cold this time. In fact, she started sticking last summer.
But as mentioned, by jiggling it before taxying, or just turning around bend
on the way to the active, she would unstick. It wasn't a real problem until
just before Xmas. As I was getting in, a friend jumped on. We are both
biggish and I felt that strut give way. It sunk more than normal.

The inspection has revealed that it practically lost all its nitrogen. And
now there is a tiny leak.

A friend of mine, an engineer for the UK PFA, something like your EAA, had a
look and reckons the o-rings have "gone". He suggests changing them and the
valve (!?). Hence, I will take it to my engineer but wanted to read more
about the thing.

Once again, thanks for your help.

Gus
EGWE

>
>> You could try brushing some STP on the outside of the exposed strut.
>> It is amazing how a tiny amount of STP will reduce elastomeric seal
>> friction for many cycles, but it will probably have to be replaced
>> (rebrushed) every few weeks. From my experience in hydraulics, it
>> would cut friction easily in half for many cycles.
>
>

In the "old days" (WWII), they sold sealed envelopes with a pad soaked
in 5606 hydraulic oil especially for the purpose of keeping the strut
oiled up. After some time, it was determined that keeping the polished
struts oiled up and hanging in the breeze actually attracted more dirt
and bunged up the seals anyway. So, the practice was discontinued.
Go figure
Mike

>
> Jay, I live in England and this winter is turning out to be quite warmish.
> So it's not the cold this time. In fact, she started sticking last summer.
> But as mentioned, by jiggling it before taxying, or just turning around bend
> on the way to the active, she would unstick. It wasn't a real problem until
> just before Xmas. As I was getting in, a friend jumped on. We are both
> biggish and I felt that strut give way. It sunk more than normal.
>
> The inspection has revealed that it practically lost all its nitrogen. And
> now there is a tiny leak.
>
> A friend of mine, an engineer for the UK PFA, something like your EAA, had a
> look and reckons the o-rings have "gone". He suggests changing them and the
> valve (!?). Hence, I will take it to my engineer but wanted to read more
> about the thing.
>

Ahhhh. Now that you mention that one has gone flat, that puts a
different complexion on the discussion.

A common technique to extend the life of a leaking seal that really does
work is Granville Strut Seal. It is a bit of a chore to get the stuff
into the struts, but most report that it does work well and can extend
the life of leaking/sticking seals by several years. I actually used it
to seal up a NEW nose strut seal job.

It is relatively inexpensive, but then again so are a new set of seals
and labor. And yes, it is recommended that the valve cores are replaced,
if not the valve bodies too.

Good Luck,
Mike

Mike,

Thanks for the advice. The engineer has suggested changing the seals and
valves. However, I am concerned with the fact that a new set can stick
relatively soon again. Oh well, we might then have to buy the Granville
Strut Seal.

Once again, thanks to all for the advice.

Gus
England

"Mike Spera" > wrote in message
...
>
>>
>> Jay, I live in England and this winter is turning out to be quite
>> warmish. So it's not the cold this time. In fact, she started sticking
>> last summer. But as mentioned, by jiggling it before taxying, or just
>> turning around bend on the way to the active, she would unstick. It
>> wasn't a real problem until just before Xmas. As I was getting in, a
>> friend jumped on. We are both biggish and I felt that strut give way. It
>> sunk more than normal.
>>
>> The inspection has revealed that it practically lost all its nitrogen.
>> And now there is a tiny leak.
>>
>> A friend of mine, an engineer for the UK PFA, something like your EAA,
>> had a look and reckons the o-rings have "gone". He suggests changing them
>> and the valve (!?). Hence, I will take it to my engineer but wanted to
>> read more about the thing.
>>
>
> Ahhhh. Now that you mention that one has gone flat, that puts a different
> complexion on the discussion.
>
> A common technique to extend the life of a leaking seal that really does
> work is Granville Strut Seal. It is a bit of a chore to get the stuff
> into the struts, but most report that it does work well and can extend the
> life of leaking/sticking seals by several years. I actually used it to
> seal up a NEW nose strut seal job.
>
> It is relatively inexpensive, but then again so are a new set of seals and
> labor. And yes, it is recommended that the valve cores are replaced, if
> not the valve bodies too.
>
> Good Luck,
> Mike