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CIES fuel sender gasket question ?

Larry DeCamp

Well Known Member
My Cies senders are impressive, with billet machined/anodized components and absolutely friction free. However, it comes with a rubber gasket. There are archives referencing leaky rubber Vans sensors and recommendations to eliminate the gasket and substitute proseal. That works well !
Cies would not supply a rubber gasket if they didn?t feel they work, BUT, rubber is rubber and compression sets. So, does anyone have experience with the Cies units to share ?
 
When we installed CiES fuel sanders in another aircraft we ran into issues with the gasket height stack up. We called CIES and they laser cut gaskets out of fiber gasket material for us. I might suggest that you consider staying with the same installation method that is commonly used by RV builders. It seems to work and at the end of the day the CiES sender is not different from a resistance sender as far a mounting and sealing go.

Just out of curiosity, are you using the single sending unit in each tank or the two senders per tank that CiES recommends because of the RV wing dihedral?

- larosta
 
Larosta

Thanks for the input. Just one sensor per tank. My main objective was to know ( with certainty) what is left near empty. Since Vans senders yield varying results, I installed Aircraft Extras low level sensors in my -3, and the no alcohol MoGas ate the sensors and they leak.
So, for my -4 project, I said ENOUGH !, and ordered CIES based on their reputation . One option is to use fuel lube on the rubber, but Proseal only (no rubber) is the proven path.
 
Belts and suspenders

On my -14 I used the gasket provided. They use this on all of their Cirrus installations. However I did proseal the perimeter and all of the screws. I?m a long way from flying. I think it is sealed very well.
 
I was looking at the cies website but did not see any mention of Van?s aircraft. What model did you purchase for the 14
 
I did not use the gasket on the installation on my 12 tank. I just followed Vans plans which called for sealant. So far so good after about 10 hours of flying.
 
...Just out of curiosity, are you using the single sending unit in each tank or the two senders per tank that CiES recommends because of the RV wing dihedral?

Current pricing is just over $600 per sender. I'm having a hard time convincing myself I need $2400 worth of fuel senders, when fuel burn can be monitored via the EFIS.

I'm leaning toward one sender per (Sky Designs extended range) tank and accepting the inaccurate "Full" indication caused by wing dihedral.
 
I’ve had Cies senders in my 182 for 5 years, installed with just the rubber gasket. No leaks. Since 1971, that plane has had no sender leaks with either a cork or rubber gasket.

I’ve got dual Cies senders on my shelf to go in my SkyDesigns ER tanks. I’ll likely go the Proseal and no gasket route.
 
Another possiblity?

According to my neighbor with an RV-10, standard tanks and the stock SW senders - he burns 8-12 gallons out of a tank before seeing a decrease in fuel quantity.

With full ER tanks in an RV-10 (41.5 gallons), that number will now be 20-24 gallons using a single sender.

No argument that (a) the CiES senders were pricey and now are even more so and (b) you can easily monitor calculated fuel burn using a fuel flow sensor and your EFIS.

One other possibility for the ER tanks is to use four SW senders (two in each tank) and connect them to the four quantity inputs on the GEA24. You have to do some mental math of course. Not ideal, but maybe a lower cost option if you have a Garmin panel.
 
According to my neighbor with an RV-10, standard tanks and the stock SW senders - he burns 8-12 gallons out of a tank before seeing a decrease in fuel quantity.

With full ER tanks in an RV-10 (41.5 gallons), that number will now be 20-24 gallons using a single sender.


No argument that (a) the CiES senders were pricey and now are even more so and (b) you can easily monitor calculated fuel burn using a fuel flow sensor and your EFIS.

One other possibility for the ER tanks is to use four SW senders (two in each tank) and connect them to the four quantity inputs on the GEA24. You have to do some mental math of course. Not ideal, but maybe a lower cost option if you have a Garmin panel.

I reached out to Ken at Sky Designs.

His calculation is that 8.7 gallons will need to be burned (in each tank) before a single-sender installation will register less than Full.
 
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