Today's Message Index:
----------------------
1. 05:33 AM - Re: Fuel Cap O ring and Air Compressor (A. Dennis Savarese)
2. 05:34 AM - Re: Fuel Cap O ring and Air Compressor (Scott Poehlmann)
3. 06:42 AM - Re: Air system problem.... (Roger Kemp)
4. 07:11 AM - Re: Air system problem.... (A. Dennis Savarese)
5. 10:52 AM - Re: Air system problem.... (Brian Lloyd)
6. 12:41 PM - Re: OSH arrivals (isaligman@saligman.com)
7. 02:58 PM - Re: Fuel Cap O ring and Air Compressor (Sarah Tobin)
8. 03:29 PM - Re: Fuel Cap O ring and Air Compressor (Sarah Tobin)
9. 06:46 PM - Re: Air system problem.... (Yak Pilot)
10. 06:50 PM - Re: Air system problem.... (Yak Pilot)
11. 06:57 PM - Re: Fuel Cap O ring and Air Compressor (Yak Pilot)
12. 09:06 PM - Master Rod Clearance (Graeme Frew)
Message 1
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| Subject: | Re: Fuel Cap O ring and Air Compressor |
My guess is the "auto shut-off" might be as simple as the pop-off valve,
which is in effect, an "auto shut-off". Troubleshooting leaks, as Mark
says, can sometimes be very difficult. But the tried and true soapy
water spay does work. Somewhat difficult to use when the engine is
running though. Use Mark's suggestion of pressurizing the line back
toward the compressor.
You can also put a small balloon on the same line that attaches to the
input side of the snot bottle. That's the line that goes to the banjo
fitting on the compressor. Start the engine and if the balloon
inflates, the compressor, shear coupling, output check valve and banjo
fitting should be OK.
The banjo fitting on the output check valve of the compressor has crush
washers on either side of it. That is where potential leaks usually
occur. Tighten the bottom fitting at the banjo fitting.
Dennis
----- Original Message -----
From: Yak Pilot
To: yak-list@matronics.com
Sent: Saturday, July 21, 2007 5:46 PM
Subject: Re: Yak-List: Fuel Cap O ring and Air Compressor
Smash, more times than not, failure to get compressed air is not a
compressor problem. Of course it is the natural thing to jump on but be
careful. You might go through a lot of hard work and money if you just
leap on the compressor without running other tests first. You said: "My
compressor has an auto shut off" and is not refilling when I fly". Ok,.
what do you mean EXACTLY by an "auto shut off" ??? What you probably
mean is that you have some type of reliever valve. This can be
something so simple as a remote method to open your snnot valve, to more
elaborate electrical valves that basically vent the compressor output to
free, or outside air. In other words, they do not compress anything
anymore. So can you describe this device please?
In many case, if you have a hard line leading from the compressor
banjo fitting to the snot valve, this can crack and your compressed air
will just leak out the crack.
You can also have a bad, or leaky banjo fitting on the bottom of the
compressor itself. This is VERY common. It is hard to troubleshoot this
stuff without some hand made tools and fittings, but here is a hint.
Try to find some fittings so that you can take the air line that runs
over to the snot valve off... at the snot valve. Now connect (anyway
you can) a source of air to the line you just took off. Blow air
BACKWARDS through this line towards the compressor. Listen for leaks.
When you find them, there is your problem.
Be VERY suspicious of the banjo fitting on the bottom of the
compressor.
Mark Bitterlich
N50YK
Sarah Tobin <aerobaticgirl@yahoo.com> wrote:
I have two issues and would like advice/help from anyone willing to
provide it.
1. Need to find an O ring for my fuel cap that has rotted and now
leaks fuel whenever I'm vertical or pushing. Where would I find one?
2. My compressor has an auto shut off and is not refilling when I
fly. It is holding air fine, and starts fine on when I refill, but
doesn't refill at all while running. Snot valve is clear and no obvious
problems on the lines external to compressor. I believe the problem to
be in the compressor itself. I have heard that you have to fashion a
special tool to get in there. Is this true, if so advice please.
Smash
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| Subject: | Re: Fuel Cap O ring and Air Compressor |
Hi Sarah,
If it has an overboard dump, then I agree that the most likely places
for failure (not necessarily in order) are:
1) at the banjo fitting from the compressor to its output line
2) at any conversion fitting (if one exists) in the line to the
overboard dump valve
3) in the overboard dump valve itself
4) in any fitting after the one-way valve, assuming there is a one-way
valve between the compressor and the tank (if there isn't, get one. They
aren't terribly expensive {~$150} and may save your
compressor)--ESPECIALLY the start valve (which is actually behind the
panel on the left) and is a real b*tch to get to.
5) the shear coupling to the compressor
Good luck, I spent the better part of last fall starting my plane from
scuba bottles whilst trying to psych out a problem which was in the
start valve the whole time. If it turns out to be that, let me know, and
I'll give you the parts list and plumbing details of the solenoid start
valve I put on mine to fix the problem.
Scott
Sarah Tobin wrote:
> Yeah, sorry, it dumps overboard. Seems as if the problem is one of
> three things
>
> 1. The dump valve is stuck open
> 2. There is a leak in the line between the pump and the check valve
> 3. Shear shaft is done busted
>
> Would you guys agree?
>
> */Scott Poehlmann <scott-p@texas.net>/* wrote:
>
>
> Hi Sarah,
>
> For the O-rings, I'd start with calling Hubie Tolson (I have his
> number
> around here somewhere if you don't). Failing that, I THINK that
> George
> Coy has some. Worst case, WLAC in England has them at pound-wise
> prices...
>
> Is there a cut-off valve for the compressor? Mine has a solenoid
> set-up
> which dumps overboard unless I actuate a switch to charge the tank.
> Otherwise I am not sure what you mean by an "auto-shut-off". The
> compressor runs all the time the engine is running. It's just a
> matter
> of where the air goes (into the bottle or overboard). Most 55's
> did NOT
> come from the factory with the compressor, so you'll need to go
> and look
> at exactly how yours is plumbed. I can send you a diagram of mine
> if you
> wish, but unless your came into the US through Scott Erickson, it is
> UNLIKELY that your is plumbed the same way...
>
> Scott
>
> Sarah Tobin wrote:
> > I have two issues and would like advice/help from anyone willing to
> > provide it.
> >
> > 1. Need to find an O ring for my fuel cap that has rotted and now
> > leaks fuel whenever I'm vertical or pushing. Where would I find one?
> >
> > 2. My compressor has an auto shut off and is not refilling when I
> > fly. It is holding air fine, and starts fine on when I refill, but
> > doesn't refill
> ------------------------------------------------------------------------
> Shape Yahoo! in your own image. Join our Network Research Panel
> today!
> <http://us.rd.yahoo.com/evt=48517/*http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7>
>
>
> *
>
>
> *
>
Message 3
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| Subject: | Air system problem.... |
Tim,
How old are your flexible brake lines. Both from the fitting to the brakes
that disappears into to the wing to the right and left of the gear well. It
then attaches to a flexible line that runs along the spar through the side
of the fuselage. Ultimately connecting to the proportionating valve behind
the fuel tanks in that hell hole in front of your rudder bar. I found that I
had a push rod rubbing on one of the aluminum airlines there.
Just one experience I have had with the air system on the 50.
Doc
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Tim Gagnon
Sent: Saturday, July 21, 2007 10:35 PM
Subject: Yak-List: Air system problem....
I will try to be as specific as I can about the issue....
Yak-50....
A bit of history is in order. The primary side bottle failed and needed to
be replaced. No Yak-50 size bottle (6 liters) on the planet so I opted for a
-52 bottle (11 liters). Got said bottle and knew it was NOT going where the
smaller bottle came from. SO......built up some structure forward of the
batteries and mounted the bottle there. (Moved the batt's up too and built a
cargo box where the batts were)
Anyway...We did a retraction test at annual and did not notice any leaks at
the gear. No leaks elsewhere that we could find. So, a few weeks pass and
the airplane develops an air problem. Here is what I am doing and what the
airplane IS NOT doing.
Normal ops.
Prior to start:
* 50 atms PRIOR to opening the valve.
* Open the valve, the pressure drops about 30+ atms to around 20.
* Starts...slower due to lower pressure...but starts.
* Long Taxi.....pressure comes up slowly to about 30-35.
* Take off...gear nearly kills my pressure coming up. Drops back to about
20. (Today, I had to put some negative on the gear to get it to lock up)
*Fly around a bit and the thing makes air like its on crack. Great pressure
and pop off valve works good.
* Gear down...and there goes about 30+ atms! (I now put the gear down a
little sooner to make sure there is plenty of press for brakes and in the
event I need to bring gear up for GA.)
Land.....Run the airplane up and let pressure build back up to about 50
atms, shut off the main valve (which reveals a climb in guage pressure), and
kill the engine. Chocks in...off to the house.
A week or so later and I have about .5 less atms. Not a huge loss. But go to
fly, and it is back to what I listed above.
Here are a few observations:
1.) No leaking sound near the rams.
2.) No hissing from the gear handle. (A fine mist of tool oil comes out from
servicing)
3.) Holds air well after a few days of sitting. Very little loss.
4.) Gear down..takes some time making air. (low RPM?)
5.) Gear up, makes silly amounts of air. (high RPM?)
Now today, I had a slow left main. Positive and Negative g's were needed to
get up/down lock. I am not sure if that is "lower" pressure issue OR a leak
on that side.
Is that very clear?
Thanks in advance! I would get a simpler airplane but I am addicted to this
problem child. I just cannot seem to kick the habit.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=125145#125145
Message 4
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| Subject: | Re: Air system problem.... |
Doc's push rod rubbing could easily be heard when moving the stick left to
right. Quite apparent. Remove the lower wing root panel and look at the
aileron push rod going through the right side of the fuselage and you will
see where the potential problem is. The pneumatic lines are VERY close to
the aileron push rod.
As for Tim's problem, if you've never pulled the landing gear actuators, you
really need to do that and have them overhauled. With the pressure dropping
30+ ATM's when you cycle the gear, most likely the seals inside the actuator
have gone T.U.
If you want to do a bit of isolating the problem, put the airplane on jacks
and pull the flexible lines off one of the actuators and plug the flexible
hose ends. Bring the pressure in the system back to 50 ATM's. Open the
main air valve and see if the pressure drop remains the same. If it still
drops 30+ ATM's then do the same thing to the other side.
Dennis
----- Original Message -----
From: "Roger Kemp" <viperdoc@mindspring.com>
Sent: Sunday, July 22, 2007 8:42 AM
Subject: RE: Yak-List: Air system problem....
>
> Tim,
> How old are your flexible brake lines. Both from the fitting to the brakes
> that disappears into to the wing to the right and left of the gear well.
> It
> then attaches to a flexible line that runs along the spar through the side
> of the fuselage. Ultimately connecting to the proportionating valve behind
> the fuel tanks in that hell hole in front of your rudder bar. I found that
> I
> had a push rod rubbing on one of the aluminum airlines there.
> Just one experience I have had with the air system on the 50.
> Doc
>
> -----Original Message-----
> From: owner-yak-list-server@matronics.com
> [mailto:owner-yak-list-server@matronics.com] On Behalf Of Tim Gagnon
> Sent: Saturday, July 21, 2007 10:35 PM
> To: yak-list@matronics.com
> Subject: Yak-List: Air system problem....
>
>
> I will try to be as specific as I can about the issue....
>
> Yak-50....
>
> A bit of history is in order. The primary side bottle failed and needed to
> be replaced. No Yak-50 size bottle (6 liters) on the planet so I opted for
> a
> -52 bottle (11 liters). Got said bottle and knew it was NOT going where
> the
> smaller bottle came from. SO......built up some structure forward of the
> batteries and mounted the bottle there. (Moved the batt's up too and built
> a
> cargo box where the batts were)
>
> Anyway...We did a retraction test at annual and did not notice any leaks
> at
> the gear. No leaks elsewhere that we could find. So, a few weeks pass and
> the airplane develops an air problem. Here is what I am doing and what the
> airplane IS NOT doing.
>
> Normal ops.
>
> Prior to start:
> * 50 atms PRIOR to opening the valve.
>
> * Open the valve, the pressure drops about 30+ atms to around 20.
>
> * Starts...slower due to lower pressure...but starts.
>
> * Long Taxi.....pressure comes up slowly to about 30-35.
>
> * Take off...gear nearly kills my pressure coming up. Drops back to about
> 20. (Today, I had to put some negative on the gear to get it to lock up)
>
> *Fly around a bit and the thing makes air like its on crack. Great
> pressure
> and pop off valve works good.
>
> * Gear down...and there goes about 30+ atms! (I now put the gear down a
> little sooner to make sure there is plenty of press for brakes and in the
> event I need to bring gear up for GA.)
>
> Land.....Run the airplane up and let pressure build back up to about 50
> atms, shut off the main valve (which reveals a climb in guage pressure),
> and
> kill the engine. Chocks in...off to the house.
>
> A week or so later and I have about .5 less atms. Not a huge loss. But go
> to
> fly, and it is back to what I listed above.
>
> Here are a few observations:
>
> 1.) No leaking sound near the rams.
> 2.) No hissing from the gear handle. (A fine mist of tool oil comes out
> from
> servicing)
> 3.) Holds air well after a few days of sitting. Very little loss.
> 4.) Gear down..takes some time making air. (low RPM?)
> 5.) Gear up, makes silly amounts of air. (high RPM?)
>
> Now today, I had a slow left main. Positive and Negative g's were needed
> to
> get up/down lock. I am not sure if that is "lower" pressure issue OR a
> leak
> on that side.
>
> Is that very clear?
>
> Thanks in advance! I would get a simpler airplane but I am addicted to
> this
> problem child. I just cannot seem to kick the habit.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=125145#125145
>
>
>
Message 5
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| Subject: | Re: Air system problem.... |
On Jul 21, 2007, at 11:35 PM, Tim Gagnon wrote:
> * Take off...gear nearly kills my pressure coming up. Drops back to
> about 20. (Today, I had to put some negative on the gear to get it
> to lock up)
Just remember PV=nRT. Since the volume in the gear rams remains the
same but you get a much bigger pressure change, the overall volume of
the system may have changed. Look for a restriction between the
system and the air storage reducing the overall system volume. In the
CJ6A you can accomplish this set of symptoms very easily -- by
leaving the main air valve turned off. The result will be huge
pressure change with gear retraction followed by unusually rapid
pressure recovery.
--
Brian Lloyd 3191 Western Drive
brian HYPHEN 1927 AT lloyd DOT com Cameron Park, CA 95682
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
PGP key ID: 12095C52A32A1B6C
PGP key fingerprint: 3B1D BA11 4913 3254 B6E0 CC09 1209 5C52 A32A 1B6C
Message 6
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| Subject: | Re: OSH arrivals |
All,
My plans have changed for rhe better, so it looks like I will be able to get to
Osh Thurs.
I am planning to camp unless someone has some sort of accomodation I can join onto.
I am a. great guest, I travell with an 11 pack on my keychain, cover my expenses
and know a few dirty jokes I have an airmatress in the baggage compartment.
Arrive thurs depart Sunday
Let me know,
Ira Saligman
610 324 5500
Sent via BlackBerry by AT&T
Message 7
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| Subject: | Re: Fuel Cap O ring and Air Compressor |
Does anyone have a schematic of the compressor system, I didn't see much in books
I have
Hi Sarah,
If it has an overboard dump, then I agree that the most likely places
for failure (not necessarily in order) are:
1) at the banjo fitting from the compressor to its output line
2) at any conversion fitting (if one exists) in the line to the
overboard dump valve
3) in the overboard dump valve itself
4) in any fitting after the one-way valve, assuming there is a one-way
valve between the compressor and the tank (if there isn't, get one. They
aren't terribly expensive {~$150} and may save your
compressor)--ESPECIALLY the start valve (which is actually behind the
panel on the left) and is a real b*tch to get to.
5) the shear coupling to the compressor
Good luck, I spent the better part of last fall starting my plane from
scuba bottles whilst trying to psych out a problem which was in the
start valve the whole time. If it turns out to be that, let me know, and
I'll give you the parts list and plumbing details of the solenoid start
valve I put on mine to fix the problem.
Scott
Sarah Tobin wrote:
> Yeah, sorry, it dumps overboard. Seems as if the problem is one of
> three things
>
> 1. The dump valve is stuck open
> 2. There is a leak in the line between the pump and the check valve
> 3. Shear shaft is done busted
>
> Would you guys agree?
>
> */Scott Poehlmann /* wrote:
>
>
> Hi Sarah,
>
> For the O-rings, I'd start with calling Hubie Tolson (I have his
> number
> around here somewhere if you don't). Failing that, I THINK that
> George
> Coy has some. Worst case, WLAC in England has them at pound-wise
> prices...
>
> Is there a cut-off valve for the compressor? Mine has a solenoid
> set-up
> which dumps overboard unless I actuate a switch to charge the tank.
> Otherwise I am not sure what you mean by an "auto-shut-off". The
> compressor runs all the time the engine is running. It's just a
> matter
> of where the air goes (into the bottle or overboard). Most 55's
> did NOT
> come from the factory with the compressor, so you'll need to go
> and look
> at exactly how yours is plumbed. I can send you a diagram of mine
> if you
> wish, but unless your came into the US through Scott Erickson, it is
> UNLIKELY that your is plumbed the same way...
>
> Scott
>
> Sarah Tobin wrote:
> > I have two issues and would like advice/help from anyone willing to
> > provide it.
> >
> > 1. Need to find an O ring for my fuel cap that has rotted and now
> > leaks fuel whenever I'm vertical or pushing. Where would I find one?
> >
> > 2. My compressor has an auto shut off and is not refilling when I
> > fly. It is holding air fine, and starts fine on when I refill, but
> > doesn't refill
> ------------------------------------------------------------------------
> today!
>
>
>
> *
>
>
> *
>
---------------------------------
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Message 8
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| Subject: | Re: Fuel Cap O ring and Air Compressor |
Things I tried today...
I was out changing the oil, then degreased and cleaned the engine to get a better
look at things in there, had to take a picture, will never see that engine
compartment that clean again
Anyway, no obvious tear in any hoses, everything passed the "jiggle test" nothing
loose in otherwords. there were no leaks obvious from the soapy water, but
didn't try the other method. Put the latex glove on and pulled prop thru,
I had a limp glove, didn't do a damn thing, so ....
Will try more tomorrow.
Smash
"A. Dennis Savarese" <dsavarese@elmore.rr.com> wrote:
My guess is the "auto shut-off" might be as simple as the pop-off valve,
which is in effect, an "auto shut-off". Troubleshooting leaks, as Mark says,
can sometimes be very difficult. But the tried and true soapy water spay
does work. Somewhat difficult to use when the engine is running though. Use
Mark's suggestion of pressurizing the line back toward the compressor.
You can also put a small balloon on the same line that attaches to the input
side of the snot bottle. That's the line that goes to the banjo fitting on the
compressor. Start the engine and if the balloon inflates, the compressor, shear
coupling, output check valve and banjo fitting should be OK.
The banjo fitting on the output check valve of the compressor has crush washers
on either side of it. That is where potential leaks usually occur. Tighten
the bottom fitting at the banjo fitting.
Dennis
----- Original Message -----
From: Yak Pilot
To: yak-list@matronics.com
Sent: Saturday, July 21, 2007 5:46 PM
Subject: Re: Yak-List: Fuel Cap O ring and Air Compressor
Smash, more times than not, failure to get compressed air is not a compressor
problem. Of course it is the natural thing to jump on but be careful. You might
go through a lot of hard work and money if you just leap on the compressor
without running other tests first. You said: "My compressor has an auto shut
off" and is not refilling when I fly". Ok,. what do you mean EXACTLY by an
"auto shut off" ??? What you probably mean is that you have some type of reliever
valve. This can be something so simple as a remote method to open your
snnot valve, to more elaborate electrical valves that basically vent the compressor
output to free, or outside air. In other words, they do not compress anything
anymore. So can you describe this device please?
In many case, if you have a hard line leading from the compressor banjo fitting
to the snot valve, this can crack and your compressed air will just leak out
the crack.
You can also have a bad, or leaky banjo fitting on the bottom of the compressor
itself. This is VERY common. It is hard to troubleshoot this stuff without
some hand made tools and fittings, but here is a hint. Try to find some fittings
so that you can take the air line that runs over to the snot valve off...
at the snot valve. Now connect (anyway you can) a source of air to the line
you just took off. Blow air BACKWARDS through this line towards the compressor.
Listen for leaks. When you find them, there is your problem.
Be VERY suspicious of the banjo fitting on the bottom of the compressor.
Mark Bitterlich
N50YK
Sarah Tobin <aerobaticgirl@yahoo.com> wrote:
I have two issues and would like advice/help from anyone willing to provide
it.
1. Need to find an O ring for my fuel cap that has rotted and now leaks fuel
whenever I'm vertical or pushing. Where would I find one?
2. My compressor has an auto shut off and is not refilling when I fly. It is
holding air fine, and starts fine on when I refill, but doesn't refill at all
while running. Snot valve is clear and no obvious problems on the lines external
to compressor. I believe the problem to be in the compressor itself. I
have heard that you have to fashion a special tool to get in there. Is this
true, if so advice please.
Smash
---------------------------------
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---------------------------------
Message 9
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| Subject: | Re: Air system problem.... |
Tim,
I hate to say it, but I am suspecting leakage through the gear actuators. You
need to take the hose off the UP side of the actuator (the rear of it) on both
gear when the thing is on the deck and has been sitting for awhile. Pull the
hose off both the left and right side actuators at the rear.
Now get two buddies and put one in each wheel well and have them put their finger
on the outlet of the actuator. Not the hose... the fitting on the actuator
itself.
Now open the valve in the cockpit. My guess is that you are going to get a significant
amount of air out of the actuators past the guys fingers in either
the left or right side, then it will stop. Again, my guess is that the seal is
leaking to begin with and then sealing.
It is common to lose air out of the gear system as it sits there over time.
Then when you open the valve your air system drops about 10 atmos. More than
that, and something is bad wrong.
So ok, you tried that and you got NOTHING out of either actuator? Ok, then the
next thing to take a close peak at is your starter select valve. Disconnect
the line coming out of the starter valve going to the air distributor, and repeat
same test as above. See if it is by-passing at that valve and then stopping.
It pretty much has to be one or the other... I think. Hmm. Well... just to
be on the safe side add one more test. Open snot valve. Let all air out. Now
open valve in cockpit and leave it open. Go back to snot valve and open it.
If any air comes out you have a bad check valve.
I can't think of anything else.
Mark Bitterlich
Tim Gagnon <NiftyYak50@fuse.net> wrote:
I will try to be as specific as I can about the issue....
Yak-50....
A bit of history is in order. The primary side bottle failed and needed to be replaced.
No Yak-50 size bottle (6 liters) on the planet so I opted for a -52 bottle
(11 liters). Got said bottle and knew it was NOT going where the smaller
bottle came from. SO......built up some structure forward of the batteries and
mounted the bottle there. (Moved the batt's up too and built a cargo box where
the batts were)
Anyway...We did a retraction test at annual and did not notice any leaks at the
gear. No leaks elsewhere that we could find. So, a few weeks pass and the airplane
develops an air problem. Here is what I am doing and what the airplane IS
NOT doing.
Normal ops.
Prior to start:
* 50 atms PRIOR to opening the valve.
* Open the valve, the pressure drops about 30+ atms to around 20.
* Starts...slower due to lower pressure...but starts.
* Long Taxi.....pressure comes up slowly to about 30-35.
* Take off...gear nearly kills my pressure coming up. Drops back to about 20. (Today,
I had to put some negative on the gear to get it to lock up)
*Fly around a bit and the thing makes air like its on crack. Great pressure and
pop off valve works good.
* Gear down...and there goes about 30+ atms! (I now put the gear down a little
sooner to make sure there is plenty of press for brakes and in the event I need
to bring gear up for GA.)
Land.....Run the airplane up and let pressure build back up to about 50 atms, shut
off the main valve (which reveals a climb in guage pressure), and kill the
engine. Chocks in...off to the house.
A week or so later and I have about .5 less atms. Not a huge loss. But go to fly,
and it is back to what I listed above.
Here are a few observations:
1.) No leaking sound near the rams.
2.) No hissing from the gear handle. (A fine mist of tool oil comes out from servicing)
3.) Holds air well after a few days of sitting. Very little loss.
4.) Gear down..takes some time making air. (low RPM?)
5.) Gear up, makes silly amounts of air. (high RPM?)
Now today, I had a slow left main. Positive and Negative g's were needed to get
up/down lock. I am not sure if that is "lower" pressure issue OR a leak on that
side.
Is that very clear?
Thanks in advance! I would get a simpler airplane but I am addicted to this problem
child. I just cannot seem to kick the habit.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=125145#125145
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| Subject: | Re: Air system problem.... |
Who the heck is Brian Lloyd?
Hey my friend, nice to hear from you.
Hey Tim. I forgot about the brakes. Oops. Easy mistake to make, mine are hydraulic.
Mark Bitterlich
Brian Lloyd <brian-1927@lloyd.com> wrote:
On Jul 21, 2007, at 11:35 PM, Tim Gagnon wrote:
> * Take off...gear nearly kills my pressure coming up. Drops back to
> about 20. (Today, I had to put some negative on the gear to get it
> to lock up)
Just remember PV=nRT. Since the volume in the gear rams remains the
same but you get a much bigger pressure change, the overall volume of
the system may have changed. Look for a restriction between the
system and the air storage reducing the overall system volume. In the
CJ6A you can accomplish this set of symptoms very easily -- by
leaving the main air valve turned off. The result will be huge
pressure change with gear retraction followed by unusually rapid
pressure recovery.
--
Brian Lloyd 3191 Western Drive
brian HYPHEN 1927 AT lloyd DOT com Cameron Park, CA 95682
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
PGP key ID: 12095C52A32A1B6C
PGP key fingerprint: 3B1D BA11 4913 3254 B6E0 CC09 1209 5C52 A32A 1B6C
Message 11
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| Subject: | Re: Fuel Cap O ring and Air Compressor |
Smash, the 55 is a rather unusual animal in that the air system is pretty much
different from one to the next. Some 55's had no air compressor at all! So...
it will be hard to find and use a diagram.
Using soapy water you are not going to find a leak from the compressor to the
snot valve. Why? Because without the engine running there is no air there to
begin with.
Since your aircraft is such an unusual beast, I would suggest that you need to
find some adapters that mate to American AN fittings. I made these and they
are a God Send.
I take the hose or line off that goes to the snot valve, I then hook up an air
bottle running at around 700 PSI. I then start looking for leaks.
Then I do the reverse. I take the line that I took OFF the snot valve that leads
back to the compressor, and I inject 700 PSI air into THAT. Usually, I'll
find the leak at the banjo fitting.
If you can't do what I am describing above, well... Smash, you really don't have
a choice. It's either that, or start dive bombing components. I would not
suggest the latter route.
Mark Bitterlich
Sarah Tobin <aerobaticgirl@yahoo.com> wrote:
Things I tried today...
I was out changing the oil, then degreased and cleaned the engine to get a better
look at things in there, had to take a picture, will never see that engine
compartment that clean again
Anyway, no obvious tear in any hoses, everything passed the "jiggle test" nothing
loose in otherwords. there were no leaks obvious from the soapy water, but
didn't try the other method. Put the latex glove on and pulled prop thru,
I had a limp glove, didn't do a damn thing, so ....
Will try more tomorrow.
Smash
"A. Dennis Savarese" <dsavarese@elmore.rr.com> wrote:
My guess is the "auto shut-off" might be as simple as the pop-off valve,
which is in effect, an "auto shut-off". Troubleshooting leaks, as Mark says,
can sometimes be very difficult. But the tried and true soapy water spay
does work. Somewhat difficult to use when the engine is running though. Use
Mark's suggestion of pressurizing the line back toward the compressor.
You can also put a small balloon on the same line that attaches to the input
side of the snot bottle. That's the line that goes to the banjo fitting on the
compressor. Start the engine and if the balloon inflates, the compressor, shear
coupling, output check valve and banjo fitting should be OK.
The banjo fitting on the output check valve of the compressor has crush washers
on either side of it. That is where potential leaks usually occur. Tighten
the bottom fitting at the banjo fitting.
Dennis
----- Original Message -----
From: Yak Pilot
To: yak-list@matronics.com
Sent: Saturday, July 21, 2007 5:46 PM
Subject: Re: Yak-List: Fuel Cap O ring and Air Compressor
Smash, more times than not, failure to get compressed air is not a compressor
problem. Of course it is the natural thing to jump on but be careful. You might
go through a lot of hard work and money if you just leap on the compressor
without running other tests first. You said: "My compressor has an auto shut
off" and is not refilling when I fly". Ok,. what do you mean EXACTLY by an
"auto shut off" ??? What you probably mean is that you have some type of reliever
valve. This can be something so simple as a remote method to open your
snnot valve, to more elaborate electrical valves that basically vent the compressor
output to free, or outside air. In other words, they do not compress anything
anymore. So can you describe this device please?
In many case, if you have a hard line leading from the compressor banjo fitting
to the snot valve, this can crack and your compressed air will just leak out
the crack.
You can also have a bad, or leaky banjo fitting on the bottom of the compressor
itself. This is VERY common. It is hard to troubleshoot this stuff without
some hand made tools and fittings, but here is a hint. Try to find some fittings
so that you can take the air line that runs over to the snot valve off...
at the snot valve. Now connect (anyway you can) a source of air to the line
you just took off. Blow air BACKWARDS through this line towards the compressor.
Listen for leaks. When you find them, there is your problem.
Be VERY suspicious of the banjo fitting on the bottom of the compressor.
Mark Bitterlich
N50YK
Sarah Tobin <aerobaticgirl@yahoo.com> wrote:
I have two issues and would like advice/help from anyone willing to provide
it.
1. Need to find an O ring for my fuel cap that has rotted and now leaks fuel
whenever I'm vertical or pushing. Where would I find one?
2. My compressor has an auto shut off and is not refilling when I fly. It is
holding air fine, and starts fine on when I refill, but doesn't refill at all
while running. Snot valve is clear and no obvious problems on the lines external
to compressor. I believe the problem to be in the compressor itself. I
have heard that you have to fashion a special tool to get in there. Is this
true, if so advice please.
Smash
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| Subject: | Master Rod Clearance |
A friend is putting a Yak 52 engine together but can't find the reference
for this particular clearance. Can anyone help. He is after the clearance
between the master rod to the crank web face. Apparently this clearance
controls the oil leak rate and therefor affects oil pressure and
temperature. Can anyone help. We think it is around 6 thou as in the Housai
but aren't exactly sure.
Thanks in advance.
Graeme Frew
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