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-   -   Good Quality Oil Pressure Sender? (https://vansairforce.net/community/showthread.php?t=175966)

Kooshball 10-11-2019 03:10 PM

Good Quality Oil Pressure Sender?
 
In looking for a replacement for my failed VDO oil pressure sending unit on the IO360 I see that the VDO ones have quite some negative reviews on Aircraft Spruce...so do most of the other sending units...

Is there a consensus on a good quality brand that makes a single terminal unit?

Thx

chaskuss 10-11-2019 04:56 PM

Quote:

Originally Posted by Kooshball (Post 1379324)
In looking for a replacement for my failed VDO oil pressure sending unit on the IO360 I see that the VDO ones have quite some negative reviews on Aircraft Spruce...so do most of the other sending units...

Is there a consensus on a good quality brand that makes a single terminal unit?

Thx

What are the complaints that the reviewers are posting on the ACs site? FYI VDO does not recommend using single post senders. The single post style relies on the body of the sender to make the ground connection. VDO also makes two post senders. You attach a ground wire to the second post to complete the ground independent of the body of the sending unit itself.

Charlie

moosepileit 10-11-2019 05:27 PM

Is there a Kavlico option with A GRT EIS?

The VDO not only has grounding issues, they wear unpredictably at the normal cruise point as the wiper wears the resistor- yielding false high.

Larry DeCamp 10-12-2019 04:57 AM

+1 for 3 wires
 
I just replaced my fuel pressure gauge and sender with UMA brand. It came with 3 wires to the sender plus a shield, and the gauge gets 12v from the buss. My original Vans sender and gauge varied for no apparent reason as commented by numerous other posts here. Just FWIW, I wonder if the Vans unit would be more stable with a dedicated ground run to the battery ground bus ?

chaskuss 10-12-2019 11:25 AM

VDO also has better senders
 
Quote:

Originally Posted by moosepileit (Post 1379345)
Is there a Kavlico option with A GRT EIS?

The VDO not only has grounding issues, they wear unpredictably at the normal cruise point as the wiper wears the resistor- yielding false high.

The only option on senders is the GRT P/N HS-SS-01 fuel pressure sender for fuel injected engines. Perhaps it's a Kavlico unit??? It sure is pricey, at $156. It also differs from the VDO senders in that it's stainless steel and has 4 wires, rather than 1. The VDO 1 wire senders can be purchases from GRT for $50. The VDO 1 and 2 wire senders are also available for less on Amazon and Jegs Performance [oil temp].

Do you have part numbers for Kavlico sender equivalents? The VDO pressure senders are 10 - 180 ohm units. I have a 20+ year old RMI uMonitor which uses VDO two terminal senders. The original oil pressure sender still works and is accurate. FYI, the uMonitor uses the same 10 - 180 ohm VDO senders, but with two terminals. The second terminal is used to ground the sender. Best methods would be to connect the sender grounds to the "forest of tabs" advocated in the AeroElectric Connection, or directly to the EIS. The two terminal senders are on average about $5 more than the single terminal [ground connection through the sender body] units supplied by GRT.

Below is a list of the VDO part numbers for the single terminal VDO senders supplied by GRT and VDO's two terminal equivalents. VDO recommends using 2 wire senders. The concern is that any sealant used on a 1 wire sender will impair the ground connection. The ground connection will also be affected by the multiple physical connections between the sender and the EIS.

Oil Pressure Transducer 10 bar 1wire VDO P/N 360-004 10 to 180 ohm

Oil Pressure Transducer 10 bar 2 wire VDO P/N 360-430 10 to 180 ohm

I don't know the VDO part number for the 1 wire fuel pressure sender. Below is the info for it's 2 wire equivalent. This is the low pressure sender used for carburetor engines.

Fuel Pressure Transducer 2 bar 2 wire VDO [Carb] P/N 360-043 10 to 180 ohm

OIl & Fuel Pressure Transducer 5 bar 1 wire VDO [FI] P/N 360-003 10 to 180 ohm

Oil & Fuel Pressure Transducer 5 bar 2 wire VDO [FI] P/N 360-410 10 to 180 ohm

All these senders have a 1/8" NPT fitting.

GRT uses both 5 bar [80 PSI] and 10 bar [150 PSI] oil pressure sending units, depending on the EIS's software version.

Download the GRT Troubleshooting guide for the EIS. Read pages 9 -11 regarding the oil pressure. Available at

http://grtavionics.com/media/Troubleshooting-Guide.pdf

Regarding your own problems with the VDO senders, where are/were your senders mounted? False high readings are due to open circuit or poor connections. Bad connection at the wiper would be one of several places that can happen on a 1 wire unit.

Charlie

chaskuss 10-12-2019 12:14 PM

Looks promising
 
Quote:

Originally Posted by moosepileit (Post 1379345)
Is there a Kavlico option with A GRT EIS?

The VDO not only has grounding issues, they wear unpredictably at the normal cruise point as the wiper wears the resistor- yielding false high.

Rich,
I just spent a bit of time on the Kavlico web site. Their P4056 series senders look promising. I like the use of Flourosilicone seals and the Packard Metri-Pac 150 electrical connectors. For those of you who aren't gear-heads, the Packard Metri-Pac connectors are used on all GM & Toyota [and other manufacturers] critical engine sensors. I have over 30 years experience with these connectors. They really hold up well. They are also water resistant. It also means that replacement electrical connectors are available at quality auto parts stores. That's a good feature if future replacement is ever necessary.
This series are 0 -5 volt DC, as used by GRT. They are available in the same pressure ratings [2 bar, 5 bar and 10 bar] that GRT uses. The flourosilicone seals mean that you can even use them with E10 unleaded auto fuel. The data sheet says that 1/8" NPT fittings are an available option, like the VDO units GRT uses.
I would really like to hear about your knowledge and experience with the Kavlico brand.

Charlie

RV10Pilot 10-12-2019 12:29 PM

As of July, 2012, Dynon Avionics supplies the following Kavlico fluid pressure sensors for
monitoring oil pressure, fuel pressure, and coolant pressure:
 Dynon Avionics P/N 101715-000 Kavlico Gravity Fed Fuel / Fluid Pressure Sensor ? 5 PSI
 Dynon Avionics P/N 101690-000 Kavlico Carbureted Fuel / Fluid Pressure Sensor ? 15 PSI
 Dynon Avionics P/N 101716-000 Kavlico Fuel Injected Fuel / Coolant/Fluid Pressure
Sensor ? 50 PSI
 Dynon Avionics P/N 101693-000 Kavlico Oil Pressure Sensor ? 150 PSI

https://www.dynonavionics.com/includ...sors-Rev_C.pdf

From Dynon the Oil/Fluid Pressure Sender - Kavlico, 1/8-27 NPT, 150 psi is $85

Don't know if this helps at all.

chaskuss 10-12-2019 01:31 PM

Quote:

Originally Posted by RV10Pilot (Post 1379448)
As of July, 2012, Dynon Avionics supplies the following Kavlico fluid pressure sensors for
monitoring oil pressure, fuel pressure, and coolant pressure:
snipped
 Dynon Avionics P/N 101690-000 Kavlico Carbureted Fuel / Fluid Pressure Sensor – 15 PSI
 Dynon Avionics P/N 101716-000 Kavlico Fuel Injected Fuel / Coolant/Fluid Pressure
Sensor – 50 PSI
 Dynon Avionics P/N 101693-000 Kavlico Oil Pressure Sensor – 150 PSI

snipped

From Dynon the Oil/Fluid Pressure Sender - Kavlico, 1/8-27 NPT, 150 psi is $85

Don't know if this helps at all.

Thanks, that helps, as it shows that Dynon made Kavlico senders work. The 0-5 PSI is irrelevant to RV builders. The 0-15 PSI, would, I think, be more accurate for those with engines with carburetors. That said, GRT has you enter codes so that the EIS knows what pressure or temperature range sender is being attached. Their standard senders are 2 bar [0-30 PSI], 5 bar [0-80 PSI] and 10 bar [0-150 PSI] I strongly suspect that there are other codes which would allow the use of the 0-15 PSI and )-50 PSI senders. You would have to call GRT tech support to verify that.
Those are Dynon part numbers, which is helpful to order the senders from Dynon. Could you check one of your Kavlico senders for a part number? The Kavlico P/N would look like P405x-A-E-4-[A or C].

Upon closer examination of the P4056 data sheet, I learn that the Kavlico sending units are 3 wire [5 volts in, modified voltage out, and ground] units, so can not be used as drop in replacements. :( That said, the HS-SS-01 GRT sender is also a 3 wire [albeit 12 volt] sensor. I'd have to call GRT tech support on Monday to find out if they have the capability to use these senders on the auxiliary sensor input circuits.

Charlie

moosepileit 10-12-2019 03:30 PM

Thanks, Charlie! That gives me something to work with for an upgrade.

Failure mode always the same. Cruise OP becomes 99psi. Per the GRT guide that's a bad sender. Actual cruise OP is 77psi. Grounding is extra case ground to the main forest of tabs. It shows accurate pressure at startup still. It is on a manifold on the firewall vertically threads down sender terminals on top, the vent on top is clear and free of blockage. 10 bar 360-004. Easy replacement, just a pain having a recurring short 2 year lifespan twice now.

Always checked with a mechanical guage tied in for a ground run, temporarily replacing the sender to make sure it isn't the engine.

Kooshball 10-13-2019 07:47 AM

Lots of good info; thank you.


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