Today's Message Index:
----------------------
1. 12:28 AM - Re: Re: Air Leak Advice (Richard Goode)
2. 06:34 AM - Re: Air Leak Advice (LawnDart)
3. 06:54 AM - Re: Re: Air Leak Advice (migfighter42)
4. 07:22 AM - Re: Re: Air Leak Advice (Bitterlich, Mark G CIV NAVAIR, WD)
5. 07:29 AM - Re: Re: Air Leak Advice (A. Dennis Savarese)
6. 07:59 AM - Re: Air Leak Advice (AcroGimp)
7. 12:57 PM - Re: Re: Air Leak Advice (Bitterlich, Mark G CIV NAVAIR, WD)
8. 06:20 PM - Re: Air Leak Advice (AcroGimp)
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| Subject: | Re: Air Leak Advice |
Are you sure the compressor is turning? There is a shear coupling between
engine and compressor held together with soft rivets, which is designed to
shear if the load from the compressor becomes too great, and it then stops
turning.
As others have suggested, a rubber glove on either inlet or exit to the
compressor will confirm this.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of AcroGimp
Sent: 21 April 2015 04:25
Subject: Yak-List: Re: Air Leak Advice
4-20-15 Update
So I did a couple engine runs today to see if I could build any pressure and
still no joy - no indication of pumping up on the gage and nothing out of
the snot valve on shutdown.
Will try the rubber glove test on compressor intake on Thursday AM, and if
that shows good will replace crush washers at banjo (most likely/most hoped
for right now).
Want to verify that just pulling a few blades through should be enough to
see if compressor is sucking air through filter.
If compressor is sucking and banjo fitting doesn't fix it, would seem like
line from banjo to snot valve, or snot valve itself would be next most
likely culprit.
I don't want to just shotgun it so advice appreciated.
'Gimp
--------
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441072#441072
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| Subject: | Re: Air Leak Advice |
Quite common for the flare of the steel line from compressor to snot bottle to
crack at the snot bottle.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441088#441088
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| Subject: | Re: Air Leak Advice |
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Message 4
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| Subject: | Re: Air Leak Advice |
Just commenting again that there is a lot of "stuff" that can leak between the
compressor and snot valve. The rubber glove trick vis--vis checking the compressor
is of course a good check. But you want to be darn sure that the compressor
is not pumping up before you remove it. Darn sure. However, listening
for leaks on that line is impossible with the engine running, obviously. Consider
reverse pressurizing the line to the compressor with the engine not running.
You will hear any leaks almost immediately. Otherwise you are just dive
bombing. If you have the rigid line with a loop in it going from compressor
to snot valve, I have seen these crack on at least three occasions now.
Mark
-----Original Message-----
From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of migfighter42
Sent: Tuesday, April 21, 2015 9:53 AM
Subject: Re: Yak-List: Re: Air Leak Advice
I was going to say the same thing. If it's leaking (banjo, valves) you should see
something. Sadly, it probably is the accessory to compressor drive shaft. It
has a frangible link that has failed. The compressor is HARD to get off. Call
Jill at M-14, they have some good tools and tricks to help you out. I had to
replace mine when the prop popped backwards on a shutdown. Lots of fun...
Bill Culberson
Red Star Aero Services
-------- Original message --------
From: Dan Payne <dantpayne@icloud.com>
Date:04/20/2015 10:44 PM (GMT-06:00)
Cc:
Subject: Re: Yak-List: Re: Air Leak Advice
How long after take off have you run the prop at 100%?
You may have sheared the drive on the engine driven compressor...
Keep 'em Flyin',
Dan Payne
Owner, Pilot, A&P-IA
(423)-544-8946
Volunteer Aero Services
Dallas Bay Skypark
1824 E Crabtree Road
Hixson, TN 37343
"Where Airworthiness Means Business!"
> On Apr 20, 2015, at 11:24 PM, AcroGimp <jlknolla@aol.com> wrote:
>
>
> 4-20-15 Update
>
> So I did a couple engine runs today to see if I could build any pressure and
still no joy - no indication of pumping up on the gage and nothing out of the
snot valve on shutdown.
>
> Will try the rubber glove test on compressor intake on Thursday AM, and if that
shows good will replace crush washers at banjo (most likely/most hoped for
right now).
>
> Want to verify that just pulling a few blades through should be enough to see
if compressor is sucking air through filter.
>
> If compressor is sucking and banjo fitting doesn't fix it, would seem like line
from banjo to snot valve, or snot valve itself would be next most likely culprit.
>
> I don't want to just shotgun it so advice appreciated.
>
> 'Gimp
>
> --------
> Owner/Pilot N6209F 1987 Yak-52
> COMM/ASEL/IFR/HP-Complex/TW
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=441072#441072
>
>
>
>
>
>
>
>
>
>
) {l 7 r h M4 Mi z . ' N jB &j)E R '
Ey n j j +
j| n )b ' !j ' + + I r yhi k k h y ! ! j ~m '
o j j +a a 0 k x & 4N4 X@E9
I& z j ( l V j ^Y ky m ~ ' hm ~ ' o .+- & *'Y
. + :W @vh j ~m ' o{k 0 k x & ' o
Message 5
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| Subject: | Re: Air Leak Advice |
If you suspect or find that the hard line between the banjo fitting on
the compressor and the input to the snot bottle is cracked, Doug Sapp
has a flexible replacement line.
Dennis
A. Dennis Savarese
334-546-8182 (mobile)
www.yak-52.com
Skype - Yakguy1
On 4/21/2015 9:21 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote:
>
> Just commenting again that there is a lot of "stuff" that can leak between the
compressor and snot valve. The rubber glove trick vis--vis checking the compressor
is of course a good check. But you want to be darn sure that the compressor
is not pumping up before you remove it. Darn sure. However, listening
for leaks on that line is impossible with the engine running, obviously. Consider
reverse pressurizing the line to the compressor with the engine not running.
You will hear any leaks almost immediately. Otherwise you are just dive
bombing. If you have the rigid line with a loop in it going from compressor
to snot valve, I have seen these crack on at least three occasions now.
>
> Mark
>
>
> -----Original Message-----
> From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of migfighter42
> Sent: Tuesday, April 21, 2015 9:53 AM
> To: yak-list@matronics.com
> Subject: Re: Yak-List: Re: Air Leak Advice
>
> I was going to say the same thing. If it's leaking (banjo, valves) you should
see something. Sadly, it probably is the accessory to compressor drive shaft.
It has a frangible link that has failed. The compressor is HARD to get off. Call
Jill at M-14, they have some good tools and tricks to help you out. I had
to replace mine when the prop popped backwards on a shutdown. Lots of fun...
>
>
> Bill Culberson
> Red Star Aero Services
>
>
> -------- Original message --------
> From: Dan Payne <dantpayne@icloud.com>
> Date:04/20/2015 10:44 PM (GMT-06:00)
> To: yak-list@matronics.com
> Cc:
> Subject: Re: Yak-List: Re: Air Leak Advice
>
>
> How long after take off have you run the prop at 100%?
>
> You may have sheared the drive on the engine driven compressor...
>
> Keep 'em Flyin',
>
> Dan Payne
> Owner, Pilot, A&P-IA
> (423)-544-8946
>
> Volunteer Aero Services
> Dallas Bay Skypark
> 1824 E Crabtree Road
> Hixson, TN 37343
>
> "Where Airworthiness Means Business!"
>
>
>> On Apr 20, 2015, at 11:24 PM, AcroGimp <jlknolla@aol.com> wrote:
>>
>>
>> 4-20-15 Update
>>
>> So I did a couple engine runs today to see if I could build any pressure and
still no joy - no indication of pumping up on the gage and nothing out of the
snot valve on shutdown.
>>
>> Will try the rubber glove test on compressor intake on Thursday AM, and if that
shows good will replace crush washers at banjo (most likely/most hoped for
right now).
>>
>> Want to verify that just pulling a few blades through should be enough to see
if compressor is sucking air through filter.
>>
>> If compressor is sucking and banjo fitting doesn't fix it, would seem like line
from banjo to snot valve, or snot valve itself would be next most likely culprit.
>>
>> I don't want to just shotgun it so advice appreciated.
>>
>> 'Gimp
>>
>> --------
>> Owner/Pilot N6209F 1987 Yak-52
>> COMM/ASEL/IFR/HP-Complex/TW
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=441072#441072
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> ) {l 7 r h M4 Mi z . ' N jB &j)E R '
> Ey n j j +
> j| n )b ' !j ' + + I r yhi k k h y ! ! j ~m '
o j j +a a 0 k x & 4N4 X@E9
> I& z j ( l V j ^Y ky m ~ ' hm ~ ' o .+- & *'Y
. + :W @vh j ~m ' o{k 0 k x & ' o
>
>
Message 6
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| Subject: | Re: Air Leak Advice |
Thanks guys. I am paranoid about the compressor drive and it will be first thing
I check Thursday AM by doing the rubber glove check on the compressor outlet.
I am guessing just put a glove on the outlet and tape it up or rubber band it tight
then pull 6-9 blades through to see if it pumps up any.
Assuming that checks OK, I will clean the little valve and piston there before
reassembling with new crush washers and trying again.
While the cowl is open and before I totally reassemble the banjo fitting I will
try and pressurize the hard line to the snot bottle from the banjo side although
I don't have shop air, just a tiny portable compressor used for filling tires
but I would think that may be enough.
There is a possibility that the snot valve is stuck open (unable to check while
doing engine runs solo) and this should show that if there are no apparent leaks
in the hard line. I might be able to drag it over to a nearby hangar and
use their shop air but that is not a given.
As gunked up as the check valve was I wouldn't be surprised if the snot valve was
in similar shape although it was cleaned during the conditional last August
according to mechanic (~60 hrs since). I do plan to basically just walk through
overhaul of all of the valves (snot valve and PRV remain on the firewall,
than possible fuselage mounted valves) but I am trying to pace myself from a budget
and frustration standpoint.
'Gimp
--------
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441093#441093
Message 7
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| Subject: | Re: Air Leak Advice |
Gimp,
You can reverse pressurize the line by going all the way up to the firewall check-valve
and taking it off there. Back feeding it there will then also check
the snot valve for leaks.
The compressor is pumping these lines up to 730 (or so) PSI. Your tire compressor
will do 120, ... maybe. The problem is that you want to reverse pressurize
the lines, then shut the valve and have everything totally silent listening,
or using soap and water looking for bubbles, or an ultrasonic leak detector
if you happen to be so lucky to have one of those, and better yet by watching
the line pressure and seeing how fast it decreases.
However, when you try to check for leaks with a system that uses 730 PSI, at 120
PSI with a compressor that does not have a shut-off isolation valve, you get
to the point where you really don't conclusively have the answer.
If you find the leak with 120 PSI, then GREAT!
If you don't find the leak with 120 PSI of air, then that does not prove that there
is not a leak. You have to test "stuff" under the same operating conditions
that they experience in flight, or with the engine running (not easy).
Point of fact: If you own a Russian or Chinese aircraft that starts and operates
using compressed air at 730 PSI, then you need to have a source of air at that
same pressure or above, typically a SCUBA bottle, but it can be whatever you
come up with really. If you don't have that available, then consider it one
of your highest priorities to obtain. You needed it.... yesterday, if you get
my point. It is just a matter of time until you run out of air and need it
for OTHER reasons. The really GOOD set-up is to have some kind of pressure regulator
with gage available. The same kind of thing welders have, but capable
of having outlet pressure controllable to 700 PSI or so. What I am trying
to suggest gracefully is that you not try to just use whatever you have. If you
want to test it right, then you need to test it with the right equipment and
not whatever you happen to have in the garage... some may not agree, but if
you pull that compressor off and find there is nothing wrong with it.... you will
then know for LIFE what I am talking about.
Question: How many hours are on that compressor?
Put the glove on the air INTAKE and not the output. It should suck it in ....
I would not put it on the output first. Read what Dennis said to you in that
regard.
With the right tests using the right equipment you will get definitive results.
Doing it with less than that and I will wish you "Good Luck" :-)
Mark
-----Original Message-----
From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of AcroGimp
Sent: Tuesday, April 21, 2015 10:59 AM
Subject: Yak-List: Re: Air Leak Advice
Thanks guys. I am paranoid about the compressor drive and it will be first thing
I check Thursday AM by doing the rubber glove check on the compressor outlet.
I am guessing just put a glove on the outlet and tape it up or rubber band it tight
then pull 6-9 blades through to see if it pumps up any.
Assuming that checks OK, I will clean the little valve and piston there before
reassembling with new crush washers and trying again.
While the cowl is open and before I totally reassemble the banjo fitting I will
try and pressurize the hard line to the snot bottle from the banjo side although
I don't have shop air, just a tiny portable compressor used for filling tires
but I would think that may be enough.
There is a possibility that the snot valve is stuck open (unable to check while
doing engine runs solo) and this should show that if there are no apparent leaks
in the hard line. I might be able to drag it over to a nearby hangar and
use their shop air but that is not a given.
As gunked up as the check valve was I wouldn't be surprised if the snot valve was
in similar shape although it was cleaned during the conditional last August
according to mechanic (~60 hrs since). I do plan to basically just walk through
overhaul of all of the valves (snot valve and PRV remain on the firewall,
than possible fuselage mounted valves) but I am trying to pace myself from a budget
and frustration standpoint.
'Gimp
--------
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441093#441093
Message 8
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| Subject: | Re: Air Leak Advice |
mark.bitterlich(at)navy.m wrote:
> Gimp,
>
> You can reverse pressurize the line by going all the way up to the firewall check-valve
and taking it off there. Back feeding it there will then also check
the snot valve for leaks.
>
> The compressor is pumping these lines up to 730 (or so) PSI. Your tire compressor
will do 120, ... maybe. The problem is that you want to reverse pressurize
the lines, then shut the valve and have everything totally silent listening,
or using soap and water looking for bubbles, or an ultrasonic leak detector
if you happen to be so lucky to have one of those, and better yet by watching
the line pressure and seeing how fast it decreases.
>
> However, when you try to check for leaks with a system that uses 730 PSI, at
120 PSI with a compressor that does not have a shut-off isolation valve, you
get to the point where you really don't conclusively have the answer.
>
> If you find the leak with 120 PSI, then GREAT!
>
> If you don't find the leak with 120 PSI of air, then that does not prove that
there is not a leak. You have to test "stuff" under the same operating conditions
that they experience in flight, or with the engine running (not easy).
>
> Point of fact: If you own a Russian or Chinese aircraft that starts and operates
using compressed air at 730 PSI, then you need to have a source of air at
that same pressure or above, typically a SCUBA bottle, but it can be whatever
you come up with really. If you don't have that available, then consider it
one of your highest priorities to obtain. You needed it.... yesterday, if you
get my point. It is just a matter of time until you run out of air and need
it for OTHER reasons. The really GOOD set-up is to have some kind of pressure
regulator with gage available. The same kind of thing welders have, but capable
of having outlet pressure controllable to 700 PSI or so. What I am trying
to suggest gracefully is that you not try to just use whatever you have. If
you want to test it right, then you need to test it with the right equipment
and not whatever you happen to have in the garage... some may not agree, but if
you pull that compressor off and find there is nothing wrong with it.... you
will then know for LIFE what I am talking about.
>
> Question: How many hours are on that compressor?
>
> Put the glove on the air INTAKE and not the output. It should suck it in ....
I would not put it on the output first. Read what Dennis said to you in that
regard.
>
> With the right tests using the right equipment you will get definitive results.
Doing it with less than that and I will wish you "Good Luck" :-)
>
> Mark
>
>
>
> --
Thanks Mark. I do have a SCUBA bottle for servicing the aircraft, just don't have
a connection that would do the job as I understand it, didn't think to use
it for this. Don't have the regulating/pressure gauge but can probably put something
together looking at welder supplies. I am guessing you have a hose with
the male fitting and just plug into the b-nut on lines you want to check?
No worries about pushing for the right tools, that's why I am asking here.
'Gimp
--------
Owner/Pilot N6209F 1987 Yak-52
COMM/ASEL/IFR/HP-Complex/TW
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