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Dynon/Advanced Service Bulletin - Kavlico Pressure Sensors

Dynon

Well Known Member
Advertiser
As an organization of engineers and pilots, we at Dynon and Advanced aim to promote safety-enhancing technology, and we constantly monitor our fleet and support data for issues that arise. To that end, Dynon and Advanced have been investigating a rare but important issue that affects the Kavlico pressure sensors that are often installed in aircraft equipped with our products, and we want to ensure that this community is aware of it.

Although we don't yet have all of the answers, we're publishing what we know, asking you for your assistance and reports, and will have a product improvement that will be available for most applications in the coming days.

We'll let the bulletin speak for itself, as it has the comprehensive background, technical information, and steps for Dynon and Advanced customers to take. Please read the bulletins available here (the content is identical):

https://dynonavionics.com/bulletins/support_bulletin_050620E.php

https://www.advancedflightsystems.com/service-bulletin-050620a.php
 
Note that Van's has also published a Service Bulletin for these sensors.

https://www.vansaircraft.com/service-information-and-revisions/sb-00006/

I read your SB and it says it applies to all aircraft then it says to read the Dynon SB. Dynon says it's since 2012. My RV-8 was completed in 2009 and I checked the Optional Parts Drawings you mention in your SB and don't see any pressure sensor model numbers. Does it not apply to older RVs?

UPDATE : Disregard, mine has German VDO sensors.
 
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Does anyone have a source for the new Kavlico sensors? I have 2 of the affected sensors installed and would like to replace them when available.
 
I read your SB and it says it applies to all aircraft then it says to read the Dynon SB. Dynon says it's since 2012. My RV-8 was completed in 2009 and I checked the Optional Parts Drawings you mention in your SB and don't see any pressure sensor model numbers. Does it not apply to older RVs?

We have never directly provided or specified a specific sensor for the RV-8 (or many of the other RV models other than the RV-12/12iS and in the past the RV-14). You are directed to refer to the document for your specific manufacturer, determine whether or not you have an affected sensor using the manufacturer's document, and from there take the appropriate action. We have no way to know whether or not you have an affected sensor(s), since it would have been acquired when you purchased your avionics parts from another vendor, hence the direction to review and examine the sensors installed in your aircraft, then take appropriate action.

Our SB is intended to make you aware of the need to review applicability and act, especially given the potential risk involved should a combustible fluid sensor fail.

Hope that helps.
 
Anyone experienced similar problems with VDO pressure transducers? VDO transducers came with my sensor kit from Dynon in 2006. The kit PN is EMSKIT-L4F (for fuel injected engines). I'm sending Dynon an email questioning this as well.
 
We know of no similar leakage issues with the VDO sensors that we sold prior to 2012.
-Robert
?
Dynon Avionics
 
FWIW: This has nothing to do with the EFIS or even when it was built/installed. It has everything to do with the sensor(s) installed in your airplane. You need to check your sensor, even if you don't have one of these particular EFIS.

:cool:
 
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We have never directly provided or specified a specific sensor for the RV-8 (or many of the other RV models other than the RV-12/12iS and in the past the RV-14). You are directed to refer to the document for your specific manufacturer, determine whether or not you have an affected sensor using the manufacturer's document, and from there take the appropriate action. We have no way to know whether or not you have an affected sensor(s), since it would have been acquired when you purchased your avionics parts from another vendor, hence the direction to review and examine the sensors installed in your aircraft, then take appropriate action.

Our SB is intended to make you aware of the need to review applicability and act, especially given the potential risk involved should a combustible fluid sensor fail.

Hope that helps.

Thank you. I went and took a look and found I have some of those "Mercedes Benz" VDO sensors :D so no issues here.

 
Received an e-mail from Dynon support, the upgraded sensors are in stock and will be available for sale "within a few days".
 
After 4 years and just over 600 hours, I think I'll defer this one to the next annual - but it's been added to my checklist for that time.
 
It would be nice if Kavlico would stand behind the senders. Seems like they could offer the replacement sensors at a discount if the original were returned. Dynon and Garmin are doing the heavy lifting of notification but I have yet to hear Kavlico step up to address the defect.
 
Interestingly, the Garmin SB (and others too) specify NON-CERTIFIED aircraft in the title of the SB. I just completed (yesterday) a wiring harness and installation of a Garmin GI275 configured as an EIS on a Grumman American Cheetah. This installation, which includes the GEA24, has the same pressure sensors as the experimental version. Part numbers are the same. Under the STC, the sensors and components are spelled out and there are no other substitutions permitted. There hasn?t been a Service bulletin issued relative to this STC.
 
GI 275 Sensors

Interestingly, the Garmin SB (and others too) specify NON-CERTIFIED aircraft in the title of the SB. I just completed (yesterday) a wiring harness and installation of a Garmin GI275 configured as an EIS on a Grumman American Cheetah. This installation, which includes the GEA24, has the same pressure sensors as the experimental version. Part numbers are the same. Under the STC, the sensors and components are spelled out and there are no other substitutions permitted. There hasn?t been a Service bulletin issued relative to this STC.

The GI 275 STC installation manual calls for a 75 psi, TSO fuel pressure sensor, part number 011-04202-20, which is not the same part as the sensors mentioned in the service bulletin, the P4055-50G-E4A, part number 494-30004-02. Not carrying TSO certification, the latter were never available for installation in a certified aircraft.

Thanks,

Justin
 
How It's Made - Oil Pressure Sensors

Do a YouTube search for "How It's Made - Oil Pressure Sensors" (5:01) and you will see exactly how the Kavlico P4055 pressure senders are made (Thx Paul). I know because I "disassembled" mine and it looks just like the video.

One thing not mentioned in the video is the "vent" hole at the bottom (inside) of the electrical connector body. The vent hole's purpose is to allow for barometric pressure changes - (G - Series). The "A" series (absolute) do not have this hole.
(Don Jones - Technical Support Manager, Dynon).

This "vent" hole becomes the de facto leak path when there is a failure of the piezo resistive element, and that is what you see in the earlier video posted here - fuel leaking out of the connector body.

Specifications for P4055 Series (what we have): Sensor Type - Piezo Resistive Element, Operating Pressure Range - 0-300psi, Proof Pressure (150psi) - 300psi, Burst Pressure (150psi) - 450psi. Mine tested (to destruction) about 500 psi - so, within spec.

Specifications for P255 Series (recommended change) : Sensor Type - Ceramic Capacitor, Operating Pressure Range - 0-1000psi, Proof Pressure (150psi) - 450 psi, Burst Pressure (150psi) - 2000psi.

The P255 Series offers a significant increase in potential - and, possibly more important, a different sensor medium that may be more resistant to failure from the environment in which they live in our airplanes - as opposed to the ground bound world.

Take the above for what it's worth - but it's what I know from my testing and looking at Kavlico's website.

YMMV
 
The vent hole inside the connector body is a poor design for aircraft useage. I had an issue with my fuel pressure dropping as I climbed in altitude. As it turns out, the o ring seal and the solder sleeves I used to splice to the wires, prevented the pressure equalization hole from seeing the real outside air pressure. This caused the pressure sensor to indicate a decreasing fuel pressure with altitude. I removed the o ring seal and fixed the issue. Kavlico also makes a version of the piezoelectric sensor that has an external vent.
As an aside, I did inspect both of mine and none showed any signs of leakage after 1000 hours or so.
The Garmin SB talks about fuel systems that have a one way check valve holding pressure after engine shutdown implying the pressure may increase due to heating under cowl after engine shutdown.
 
Replacement Sensors
Replacement Kavlico sensors are available for purchase from Dynon. Dynon is not responsible for costs related to the removal and installation of the sensors

So is this normal for experimental for a company to charge for the replacement part that they sold in the first place to use with their product?
 
fuel sensor P/N

[SIZE=+2]Dear fellow RVer,[/SIZE]
[SIZE=+2][/SIZE]
[SIZE=+2]I went through this SB a couple of times and would like to know about the correct P/N to order. I tried to contact Don from Dynon four times by email but no answer. Trying to contact them by phone ended on the answering machine.
I'd like to confirm the P/N for the sensors. If I understood the SB correctly, there is only one sensor available to replace the old oil and fuel sensors, you don't offer separate sensors. The mentioned sensor and it's range covers both fluids. Am I right or where is my error in understanding?
[/SIZE][SIZE=+2] The offered P/N P255-150G-EA4 replaces the oil and fuel pressure sensor?[/SIZE]
[SIZE=+2][/SIZE]
[SIZE=+2]Thanks[/SIZE]
[SIZE=+2]Stephan[/SIZE]
[SIZE=+2]PH-LRV[/SIZE]
[SIZE=+2]RV8[/SIZE]
[SIZE=+2]10 hrs.
[/SIZE]
[SIZE=+2]
[/SIZE]
 
So is this normal for experimental for a company to charge for the replacement part that they sold in the first place to use with their product?

The industry standard - experimental or certified - is that the company bears the cost during the warrantee period (typically 1 year). After that time, it?s on the owner. Third party accessories may be included or excluded from the warrantee, read your fine print.
 
I e-mailed Dynon a couple of weeks ago when the SB was released and inquired about 2 upgraded Kavlico sensors (FP & OP). Dan at Dynon called me yesterday and said a limited number were available and they were going through the request list on a first come first serve basis.
I only ordered 1 so as not to be a "sensor hog" as replacing my FP sensor is the most critical to me. I will replace the OP sensor when they are more readily available. By the way the cost was $134.
 
[SIZE=+2]Dear fellow RVer,[/SIZE]

[SIZE=+2]I went through this SB a couple of times and would like to know about the correct P/N to order. I tried to contact Don from Dynon four times by email but no answer. Trying to contact them by phone ended on the answering machine.
I'd like to confirm the P/N for the sensors. If I understood the SB correctly, there is only one sensor available to replace the old oil and fuel sensors, you don't offer separate sensors. The mentioned sensor and it's range covers both fluids. Am I right or where is my error in understanding?
[/SIZE][SIZE=+2] The offered P/N P255-150G-EA4 replaces the oil and fuel pressure sensor?[/SIZE]

[SIZE=+2]Thanks[/SIZE]
[SIZE=+2]Stephan[/SIZE]
[SIZE=+2]PH-LRV[/SIZE]
[SIZE=+2]RV8[/SIZE]
[SIZE=+2]10 hrs.
[/SIZE]

Stephan,
The 50, 75, and 150 psi sensors (whether oil or fuel) are being replaced with the new style 150 PSI P255-150G-E4A. The 15 PSI sensor used by most carbureted sensors is being replaced by a new style 15 PSI sensor P255A-15G-E4A.
 
I guess the real question than is worn out or broken v defective. Seems like these sensors have been identified as ? not doing what they were designed to do ? ie defective. When a car part goes ? defective ? a recall ensues and you can get a manufacturers replacement. ( usually).
Sure a worn out part I need to replace on my dime but defective?
 
My new sensors arrived. The new ones are on top and the original ones on the bottom. Haven't weighed them but the new ones are clearly heavier.

Dynon gave good service, thanks!

VJk82dd.jpg


So far, none of them have been out of the packages.

Dave
 
Stephan,
The 50, 75, and 150 psi sensors (whether oil or fuel) are being replaced with the new style 150 PSI P255-150G-E4A. The 15 PSI sensor used by most carbureted sensors is being replaced by a new style 15 PSI sensor P255A-15G-E4A.




Thank you Don!!!
Best Regards
Stephan
 
Just replaced my Fuel and oil sensors. The original oil sensor was a 150 pis sensor so my oil pressure seems to be reading correctly. My fuel pressure sensor was a 50 psi sensor and the new one is a 150 psi sensor and my fuel pressure is reading 8 psi and in red whereas it should read 29 psi. I upgraded my software version from 15.3.3 to todays latest 15.4.7 and no change.
I would like to know how to change my sensor data from the 50 psi model to the new 150 psi model so my fuel pressure reading would be correct. I thought with the new software I would have the new sensor option available but I cannot find it.
Thanks
 
Search may not be working. Posted this a while back in “Safety concern with fuel pressure sender” :
I installed my 2 New sensors today - SKYVIEW. No changes to anything and my fuel pressure read 1/3 of Normal. Normal is 27, it read 9. Had to go into SETUP and select the new sensor in MAPPING. Now reads 27 as before.
 
Lucky for me, the G3X works with the VDO senders that were installed with the Blue Mountain EFIS that I was replacing. However, the BMA system read MAP from the ignition box(es) so I had to plumb for the low pressure sender, which failed out of the box. No leak, but never wavers from 32.2, which is impossible here at 7000'. Reads the same even if disconnected from the line and exposed to ambient pressure. Aerotronics (class act) are helping me out with a replacement swap but I have to say I am not impressed by this entire line of senders.
 
In my case I have VDO sensors connected to my DYNON system. It has been this way since 2013 without any problems. YMMV

:cool:
 
The new Kavlico sensors

Just replaced my Fuel and oil sensors. The original oil sensor was a 150 pis sensor so my oil pressure seems to be reading correctly. My fuel pressure sensor was a 50 psi sensor and the new one is a 150 psi sensor and my fuel pressure is reading 8 psi and in red whereas it should read 29 psi. I upgraded my software version from 15.3.3 to todays latest 15.4.7 and no change.
I would like to know how to change my sensor data from the 50 psi model to the new 150 psi model so my fuel pressure reading would be correct. I thought with the new software I would have the new sensor option available but I cannot find it.
Thanks

Ron,

I also swapped out both fuel and oil pressure sensors with the new 150 psi versions in my plane, and I had to play around a bit to get my fuel pressure to read correctly.

One thing you also need to do it update the Engine Sensor Definitions updated 5/14/2020. It has the new definitions for the new Kavlico sensors. Go to Dynon System Software for your screen, go to the bottom as it is the last item, download and install.

I will be out at my hanger in awhile, and will take a few snapshots of my settings and will post them here this afternoon when I get home, so check back tonight as I am west coast time.

Brian
 
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Where are you guys finding the new sensors, I can't find them in stock to save my life!
 
Ron,

I also swapped out both fuel and oil pressure sensors with the new 150 psi versions in my plane, and I had to play around a bit to get my fuel pressure to read correctly.

One thing you also need to do it update the Engine Sensor Definitions updated 5/14/2020. It has the new definitions for the new Kavlico sensors. Go to Dynon System Software for your screen, go to the bottom as it is the last item, download and install.

I will be out at my hanger in awhile, and will take a few snapshots of my settings and will post them here this afternoon when I get home, so check back tonight as I am west coast time.

Brian

I had already downloaded the latest last evening. My problem was under MAPPING you have select, I did not want what was showing as it was showing the old sensor information. I find select to be the incorrect wording, it should be options and when you click on the one you want then select.
You click select and when you find the one you want then press accept.
test flown this morning and all is well.
thanks
 
Good to hear

I had already downloaded the latest last evening. My problem was under MAPPING you have select, I did not want what was showing as it was showing the old sensor information. I find select to be the incorrect wording, it should be options and when you click on the one you want then select.
You click select and when you find the one you want then press accept.
test flown this morning and all is well.
thanks

Ron,

Glad that you figured it out. One thing I did, was to make the widget only show full height of 50 psi, so it looked like it did before and and not the full 150 psi of the sensor.

If you are interest, I can post my widget settings. Just let me know.

Brian
 
Picked up one today at Allied Electronics, www.alliedelec.com, phone
866-311-0869. Their stock# 70331272 for P255-150G-E4A for $120.45
They had 27 in stock when I ordered Monday night, July 20.

You sir are the man! They must have just got a batch in. Two on order! Thanks for posting or I would have never known they were back in stock here.
 
Just completing my annual condition inspection. I ordered new senders to replace my fuel sender that was subject to the service bulletin, and while I'm at it why not update the oil pressure sensor at the same time.

236-M.jpg


I went into the Dynon menu for the EMS sensor set up and changed them to the new Kavlico V2 103757-000 type. The oil pressure is where it normally was with the old VDO style sensor. However, my fuel pressure is now reading around 33 psi with the engine mechanical fuel pump and 43 psi with the boost pump on. Prior to the installation, I would see 23 psi on the engine and 33 psi with the boost pump.

I'm just wondering if anyone else has seen this happen, or if I might need to adjust the calibration values in the Dynon EMS unit for these sensors. I'm running the latest Dynon SW.
 
Just completing my annual condition inspection. I ordered new senders to replace my fuel sender that was subject to the service bulletin, and while I'm at it why not update the oil pressure sensor at the same time.

236-M.jpg


I went into the Dynon menu for the EMS sensor set up and changed them to the new Kavlico V2 103757-000 type. The oil pressure is where it normally was with the old VDO style sensor. However, my fuel pressure is now reading around 33 psi with the engine mechanical fuel pump and 43 psi with the boost pump on. Prior to the installation, I would see 23 psi on the engine and 33 psi with the boost pump.

I'm just wondering if anyone else has seen this happen, or if I might need to adjust the calibration values in the Dynon EMS unit for these sensors. I'm running the latest Dynon SW.

Bruce,
Make sure you didn't select the differential selection on the fuel pressure sensor in sensor input mapping. There are two with the same part number one diff and one not.
 
New Kavlico sensor

If anyone is curious about how to set up the Advanced Flight screen here’s what Jonathan from AFS advised me:

 
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