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TB20 fuel tank indicator fault

I’m looking for removed tank sensors analog to TB 20.
I would like to buy one or two of these.
Maybe someone can help me.
Thomas

Berlin, Germany

CIES fuel senders

I would still bench test the indicating instrument first, because changing the senders is a pretty big job.

Administrator
Shoreham EGKA, United Kingdom

Actual experience from CIES installations on TB20 (IIRC invl hours) can be found on socata.org ;-)

...
EDM_, Germany

I found this company to replace the TB 20 fuel sender. Can I get help figuring this out here?
Thomas

https://ciescorp.net/applications/small-aircraft/other/

Berlin, Germany

When installed, it is not so easy to move the float and measure the resistance. Especially where the wire resistor is obviously defective.
Are there other sources to find a sender?

Berlin, Germany

Paul and Bill Malkasian used to rework fuel senders working intermittently as yours

Paul passed on in 2015 and although I understand his son said he’d be continuing the business, I’m not sure if that’s the case now.

Paul and Bill Malkasian used to rework fuel senders working intermittently as yours. I reckon the coil is faulty, though it is a delicate job to repair. Testing the resistance with an ohm meter will confirm the fault.
I would check if CIES has produced a compatible sender for Tb20, as they are not only very accurate, they also are a definitive answer to frequently failing resistive senders

For anyone interested and to participate.
Here is the circuit for the fuel gauge. The resistance combination left Tank follows (R root + R1) // R extreme = R total.

Berlin, Germany



exactly, that’s what I mean.
The wire resistor has a defect at a specific point.
The removing is a big challenge and I’m not sure it is it possible to fix it properly. My hope was that someone has already done it .

Berlin, Germany
Thomas, before going into electronics of the indicator I´d suspect the sensor to be scrap. Most of the typical fuel sensors are the wire resistor type like in cars. So then there is a good chance the wire got a defect, by corrosion or wear. You can test the indicator by hooking a potentiometer on it to simulate the sensor. I guess 100 ohms wire potentiometer will do for testing the indicator for smooth action over the whole range. Only then care for the indicator when it does show erratic readings. On the Yak we got extremely precise readings from both indicators but these are sealed and military standards obviously. We did have defective floats of a foam plastic type when with Super 98 use and 3 decades they shrunk so much for no longer floating in fuel. The stainless type in photo will outlast us by decades I believe. Vic

vic
EDME
18 Posts
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