My TKS Panel Doesn't Fill Out

[RonM]

I have a Mooney Missile (Converted M20J to 300 hp airplane).  I had a TKS system installed about 15 years ago.  All well but in the past few years I have a problem.  On one of the horizontal stabilizers, the TKS panel doesn't get wet all the way to the end.  Sometimes about 18 inches short, but i just did it in very cold temps and half the horizontal stabilizer did not fill out.  I did have the CAV ice protection place in Kansas rebuild the TKS pump a year ago.  Yes - I was thrilled to see the TKS panel filling out when I tested it, but the old problem comes back.  I have had the repair shop purge the system and they said my panels were filling out all the way.  Same thing when I had my annual last year - which was when the re-built tks pump was installed.  I have never gotten a filter replacement, but was told my low pressure light is not coming on , so I don't need it.    I find it annoying that the one horizontal stabilizer does not always fill out (just on one side). I also wonder what if my other leading edges were free of ice, but the left horizontal stabilizer had partial ice on the leading edge.  Would that be a workable situation?  I am a very conservative pilot and have rarely used my TKS  in actual icing - so i know the system is meant to be used to get out of inadvertent ice encountered.  The TKS is not certified into known icing - but that just means I have one tks pump and one alternator. Any commentary appreciated.

[N6758N]

Do you exercise the system regularly? The membranes inside the TKS panels can dry out, I think they say it should be turned on at least once a month...

[milotron]

What he said.^^

I did this yesterday on the ground, without the engine running. I had the ice light on to confirm it's operation and there was enough voltage drop on the system with that additional load that I could hear the pump slow down.  I suspect with the engine running it should pressurize even more with the higher voltage.

Mine was slow to saturate the vertical panels on the tail as well as one panel on each wing, but they eventually got wet.

It is important to do it regularly. I liked a previous suggestion of running the pump monthly when you update the nav data. Brilliant!

 

iain

[RonM]

Yes, I have been pretty diligent about running the system monthly.  Not always, say the airplane was in service, but otherwise Yes.   I think from what the guy at CAV said - who overhauled my TKS pump, the panels should not "dry out" so easily if the system has not run for a couple of months or longer - as is commonly believed.  However, I most definitely make a point to run the system monthly.  Maybe the suggestion to do that while the engine is running is a good one?  All the other panels fill out to the end , except the one horizontal stabilizer (on the left side of the airplane.)  I guess it is an intermittent problem because I have seen it fill out.

[Guest]

I would put ground power on the be sure main buss voltage is up.  I’ve heard of applying tape over the area which flows correctly in an effort to force the dry area, Ive never tried this as we have a pressure pot.

You could also switch the stab lines at the proportioning valve to eliminate it as a cause.

Clarence

[peevee]

you can build the purge rig pretty cheaply and just purge the system per the AMM

[milotron]

Was the purge rig posted elsewhere already?

 

iain

[peevee]

11 hours ago, milotron said:

Was the purge rig posted elsewhere already?

 

iain

It's basically a pressure pot and a filter and some lines. I haven't seen it here but on other forums.

 

https://www.amazon.com/gp/product/B0045LQSG0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0030ZD7MU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

https://www.amazon.com/gp/product/B004O3OP2S/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

https://www.amazon.com/gp/product/B0092KWBY2/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 (you might need 3/16")

 

https://www.harborfreight.com/welding-cart-61316.html

 

https://www.harborfreight.com/2-1-2-half-gallon-pressure-paint-tank-66839.html

 

To hookup to your panel you will need to get a couple of TKS olives (aluminum) and nuts from your SC.

The braided stainless steel tube and the misc brass hardware coming out the other end of the filter are from a local hardware.   I just took it in and bought what was neccessary to do the final connections.  I will have to grab some photos of the brass tee on the other side.

Of course you will need an air compressor to supply the pressure can.

 

[carusoam]

Welcome aboard, Ron.

You have received some pretty good info above.

Have you talked with anyone at CAV along the way?

They have a pretty strong tech service group... if you need additional help.

https://www.caviceprotection.com/products-services/technical-support

There are a few threads around here covering the oddities of the TKS system.  Using the search function will probably get them to appear.

 

Best regards,

-a-

[RonM]

Thank you, Carusoam.  Much appreciated.  Yes, last year I consulted CAV and the proposed solution was to overhaul the TKS pump.  My mechanic sent the pump to CAV at the annual last year..  My mechanic at the annual, then received and installed the overhauled tks pump, and tested the system and said Yes - all the panels fill out.  I have observed all the panels fill out during my monthly exercise of the system, but recently half of the left horizontal stabilizer panel did not fill out.  Perhaps I could have ran the system longer.  I only gave it about 15 minutes.  I will definitely follow up with CAV again, or hopefully the panel will somehow start filling out.  I don't like the intermittent problem, because I would want full confidence if I ever need the system in actual icing conditions.  Perhaps a filter change would help, as I have never done that?  Also thanks all for the helpful comments on this topic.  Regards - RonM

[peevee]

try soaking a rag with tks fluid and wiping the panels down before you run them to break the surface tension and see if they wet out.

[aviatoreb]

47 minutes ago, RonM said:

Thank you, Carusoam.  Much appreciated.  Yes, last year I consulted CAV and the proposed solution was to overhaul the TKS pump.  My mechanic sent the pump to CAV at the annual last year..  My mechanic at the annual, then received and installed the overhauled tks pump, and tested the system and said Yes - all the panels fill out.  I have observed all the panels fill out during my monthly exercise of the system, but recently half of the left horizontal stabilizer panel did not fill out.  Perhaps I could have ran the system longer.  I only gave it about 15 minutes.  I will definitely follow up with CAV again, or hopefully the panel will somehow start filling out.  I don't like the intermittent problem, because I would want full confidence if I ever need the system in actual icing conditions.  Perhaps a filter change would help, as I have never done that?  Also thanks all for the helpful comments on this topic.  Regards - RonM

When I purchased my airplane 8 years ago from a fellow in NC, the tks had not been run in several years.  It was all dried out.  After running 15 gallons through the system, all the panels cleared out and it flowed as it should.  It takes several hours to run 15 gallons.  I did it while flying around and doing other training...in that early spring.

If that doesn't work, I know that some service stations, especially ones that are cirrus centers, have the equipment to purge the system as described above, so you don't need to build that yourself.

[peevee]

8 minutes ago, aviatoreb said:

When I purchased my airplane 8 years ago from a fellow in NC, the tks had not been run in several years.  It was all dried out.  After running 15 gallons through the system, all the panels cleared out and it flowed as it should.  It takes several hours to run 15 gallons.  I did it while flying around and doing other training...in that early spring.

If that doesn't work, I know that some service stations, especially ones that are cirrus centers, have the equipment to purge the system as described above, so you don't need to build that yourself.

to buy that cart from cav is like $6,000 so if you find a shop that has one I suspect they're going to charge accordingly.

[LANCECASPER]

10 minutes ago, aviatoreb said:

When I purchased my airplane 8 years ago from a fellow in NC, the tks had not been run in several years.  It was all dried out.  After running 15 gallons through the system, all the panels cleared out and it flowed as it should.  It takes several hours to run 15 gallons.  I did it while flying around and doing other training...in that early spring.

For what it's worth, I've only had flown a couple Mooneys that had TKS, but even though they seem like they aren't "filling out" when you first test them, when you run them long enough at first and then run them regularly they seem to work just fine. Don't expect them to distribute it perfectly even across the panel.

[aviatoreb]

22 minutes ago, LANCECASPER said:

For what it's worth, I've only had flown a couple Mooneys that had TKS, but even though they seem like they aren't "filling out" when you first test them, when you run them long enough at first and then run them regularly they seem to work just fine. Don't expect them to distribute it perfectly even across the panel.

I run it for just a couple of minutes ever month of so in the summer, and just about every flight meaning about every week, in the winter, so it will be ready to go if I need it and never really dry out.  Once its in good shape and not at all dried out just a few minutes at each run is enough to keep it that way.  I do it in flight while in process of doing something else.  Everything wets well when its in good shape.

Edited January 5, 2018 by aviatoreb

[exM20K]

24 minutes ago, LANCECASPER said:

For what it's worth, I've only had flown a couple Mooneys that had TKS, but even though they seem like they aren't "filling out" when you first test them, when you run them long enough at first and then run them regularly they seem to work just fine. Don't expect them to distribute it perfectly even across the panel.

True. Also, the horizontal stabilizer is the last surface to wet (and the first to accumulate ice).  I'd fly around with the system blasting away on high for at least a full tank or until the panel got wet. It can take some time. 

[kevinw]

I used to run mine once a month when I first bought the plane but now I run it about every 60-90 days (if it hasn't been used) and I've never had a problem. Got tired of TKS fluid dripping on my hanger floor.

[aviatoreb]

1 hour ago, kevinw said:

I used to run mine once a month when I first bought the plane but now I run it about every 60-90 days (if it hasn't been used) and I've never had a problem. Got tired of TKS fluid dripping on my hanger floor.

Often I don’t run them until fluid is streaming back but just briefly until a bit beads at leading edges.

[peevee]

21 minutes ago, aviatoreb said:

Often I don’t run them until fluid is streaming back but just briefly until a bit beads at leading edges.

makes the wing slippery. I have almost slipped off before.

[aviatoreb]

1 minute ago, peevee said:

makes the wing slippery. I have almost slipped off before.

I mean in priming them I don’t feel the need to make the wings wet, just the panels.

[Joe Zuffoletto]

The TKS panels on my Acclaim took more than 15 minutes to fill out when I would run the pump on "Normal." I mentioned this to my mechanic, and he recommended running the windshield pump for 10-15 seconds to prime the system. Sure enough, my panels now fill out in 8-10 minutes.

[M016576]

On 1/4/2018 at 6:34 AM, RonM said:

I have a Mooney Missile (Converted M20J to 300 hp airplane).  I had a TKS system installed about 15 years ago.  All well but in the past few years I have a problem.  On one of the horizontal stabilizers, the TKS panel doesn't get wet all the way to the end.  Sometimes about 18 inches short, but i just did it in very cold temps and half the horizontal stabilizer did not fill out.  I did have the CAV ice protection place in Kansas rebuild the TKS pump a year ago.  Yes - I was thrilled to see the TKS panel filling out when I tested it, but the old problem comes back.  I have had the repair shop purge the system and they said my panels were filling out all the way.  Same thing when I had my annual last year - which was when the re-built tks pump was installed.  I have never gotten a filter replacement, but was told my low pressure light is not coming on , so I don't need it.    I find it annoying that the one horizontal stabilizer does not always fill out (just on one side). I also wonder what if my other leading edges were free of ice, but the left horizontal stabilizer had partial ice on the leading edge.  Would that be a workable situation?  I am a very conservative pilot and have rarely used my TKS  in actual icing - so i know the system is meant to be used to get out of inadvertent ice encountered.  The TKS is not certified into known icing - but that just means I have one tks pump and one alternator. Any commentary appreciated.

I had 2 panels that were slow to wet (like 15 minutes plus on high, even though the low pressure light went out relatively quickly).  The left inboard most panel and the left outboard horizontal stab panel.  I purged them, had the pump overhauled.. all seemed like they worked for a week or two...  after almost a year, I finally found the problem.  

And anyone that has a similar problem should probably check this..

under the tail fairing, the lines that run to the tail horizontal stab panels run VERY close to an aluminum rib.  In my case, after trimming the airplane over the course of about 15 years, the rib sawed a hole in one of the tail panel lines!  The A&P purging the system last year didn’t catch it, but the sharp folks at professional Air in Bend, Or caught it.  To fix it- they had to remove the upper fairing on the tail, the fashion a new tube, then they covered the spar with a little piece of tube, so it wouldn’t happen again.  They fixed the other side as well.

im not saying this is exactly your problem, but it sounds like you might have pressure drop across the system somewhere downstream of the low pressure sensor and the filter... run the system and look for excessive puddles.  That spot on the tail, due to the mooney’s Articulating tail, and the fact that a bit of fluid that normally drips down from the vertical stab panel made it fairly insidious.  

[MB65E]

Welcome!! Change the filter and look for a compromised line in the tail as above post mentioned.

Possibly, The low pressure light won't come on because the filter is restricting flow and causing higher pressure. But I'm unsure on where that P switch is. 

Had a Bravo do the same thing.

-Matt

[M016576]

20 minutes ago, MB65E said:

Welcome!! Change the filter and look for a compromised line in the tail as above post mentioned.

Possibly, The low pressure light won't come on because the filter is restricting flow and causing higher pressure. But I'm unsure on where that P switch is. 

Had a Bravo do the same thing.

-Matt

The aft most belly panel... not the three “main” ones, but the one with TKS overflow tube coming out of it... has the filter mounting bracket and housing, as well as at least one, if not two of the high/low pressure switches

[PaulM]

4 minutes ago, M016576 said:

The aft most belly panel... not the three “main” ones, but the one with TKS overflow tube coming out of it... has the filter mounting bracket and housing, as well as at least one, if not two of the high/low pressure switches

For the FIKI long bodies: (M+R+TN) Official install diagrams are somewhere on Mooneyspace in one of the threads..  "TKS Drawings.pdf"

There is a schematic on mooney.com in the POH supplement:

http://www.mooney.com/en/pdf/SUPP0017F.pdf

The High pressure switch is in the body after the main pumps and before the filter, so a clogged filter triggers the high pressure warning. 

The low pressure sensors are on the  tail flow divider on the way to the two horizontal stabilizer's.  They are wired in series so if either is low the warning should trigger..