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fallowdeer

Low fuel warning light

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Hi

 

I had a similar issue early on.

 

First, I reattached the earth leading from the sender to the chassis to confirm it was grounded. I thought mine had vibrated loose.

 

Second make sure the low fuel light socket and it terminals are not earthing out on the frame that holds the instrument panel to the dash - my socket had rotated such that the terminals were earthing out on the frame.

 

Problem solved.

 

 

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I read somewhere else on the forum that the Savannah owner suggested replacing the usual fuel warning light with a flashing LED so that it grabs your attention.

 

 

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Fallow dear , That setup in the Savannahs is one of the safest I've seen. The press to test on the light is great and the whole sump Idea with the low fuel light is spot on ...all aircraft should have it.

Have heard in the past of avgas causing faulty sensor operation in the Savannah set up.......have you been running avgas ?....I don't know why it effects it.

 

I have also been wondering if the low oil warning on your standard Honda 5.5hp pump motor would work in a similar fashion, they seem to work pretty well on those engines..............Cheers .......Maj....

Avgas won't affect the sensor Ross....the way it is made and the material it is made of. It is a float with a magnet in it basically that comes up and down a shaft when it falls away from the top it closes a circuit to ground which either flashes a 12volt 10mm flashing LED which is what I put in my Sav or the 12v light bulb as in the standard kit fitting. The main problem seems to be the way the tanks are plumbed as per the kit manual there is a case where you can get a airlock in the top of the sump and that will give you a scare. A lot of Sav owners have had this. I can't get that with the way I plumbed mine as I only have all the fuel from 4 tanks going into a manifold with 4 switches then the single manifold outlet goes to one of the top inlets and other top inlet is a vent to the top of my tank so it can never get a vapour lock of air bubble

 

Mark

 

 

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Hi everyone

 

Thanks for all the replies and suggestions. I hadn't considered the possibility of an electrical fault, will be one of the things to check when I get back to the hangar. (Been away ten days hunting) This co

 

There is no air bubble at the top of the header tank, with the intermittent nature of the light coming on an electrical misconnection could certainly be the case.

 

Peter

 

 

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I ran the checks I mentioned in an earlier post and it was the sender unit. I replaced it and ran a test and it works OK. I believe it is a common problem.

 

If any of you have the air lock problem, it is easily solved by adding a breather to the top of the collector tank and running a tube up to the fuel return line to the RH tank using a kit supplied by an agent. (I was fortunate enough to have received this advice before I built).

 

Blue skies,

 

Ron.

 

 

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I've been having low fuel pressure. On the ground and up to about 5500ft it's is within range but after that it drops progressively to almost nothing on the gauge. Even with electric pump on it only increases slightly. then after a short time the low fuel light comes on. The engine never misses a beat however.

 

anyone have any ideas what's going on??

 

 

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I've been having low fuel pressure. On the ground and up to about 5500ft it's is within range but after that it drops progressively to almost nothing on the gauge. Even with electric pump on it only increases slightly. then after a short time the low fuel light comes on. The engine never misses a beat however.anyone have any ideas what's going on??

If you look at the back of your fuel pressure gauge at the top there is a rubber plug, you have to remove it or drill a small hole in it. This will let the pressure inside the case equalise and it will work normally. Worked for me and a few others.

 

Don't know why the low fuel light would come on though.

 

 

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if the fuel pressure gauge is under reading due to the internal pressure diff, then maybe there is a smal bubble in the top of the collector that expands with altitude until the float drops enough to set off low fuel light?

 

I know I could put a breather in the top of the collector but I'm not sure how to, and don't want to cut holes in the collector without sealing properly

 

 

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I plumbed mine differently to stop that air bubble getting into the top of the fuel reserve tank. You will have 2 inputs to the top f your tank and one side of your fuel tank going to each input. I put all my fuel inputs to a manifold and only used one of the inputs at the tank the other then becomes a breather back up to the top of one of the tanks

 

Mark

 

 

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I plumbed mine differently to stop that air bubble getting into the top of the fuel reserve tank. You will have 2 inputs to the top f your tank and one side of your fuel tank going to each input. I put all my fuel inputs to a manifold and only used one of the inputs at the tank the other then becomes a breather back up to the top of one of the tanks

Mark

would I work if I put a T-piece in at the collector to join the two lines, then used the spare as a breather, running it to a T-piece on the fuel return line for the engine (where it comes through the cabin)?

 

 

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If you look at the back of your fuel pressure gauge at the top there is a rubber plug, you have to remove it or drill a small hole in it. This will let the pressure inside the case equalise and it will work normally. Worked for me and a few others.Don't know why the low fuel light would come on though.

Had a look today and found the grommit. removed it and fuel pressure is perfect right up to 10,000ft.

 

thanks :)

 

 

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Drill a hole in the grommet and put it back in to keep the hornets out of your gauge.

oh yeah. hadn't thought of that. bloody things get into everything !

 

 

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Hi all,

 

is there any fuel gauge stick calibrated for the Savannah tanks that are available...or some measurements that I can duplicate.

 

thanks

 

 

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You could make your own: drain tanks, set plane level and add say, 5 litres to each tank at a time, each time marking where it gets to on dipstick until full.

 

 

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You could make your own: drain tanks, set plane level and add say, 5 litres to each tank at a time, each time marking where it gets to on dipstick until full.

The last couple of additions need to be only two litres then one litre, near the top of the tank following the wing profile. You need to isolate the tank being calibrated too or some of your volume will escape to the other side tank.

 

 

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Another useful exercise, while you're at it, is to calibrate your fuel mizer by pumping full tanks thru it.

 

 

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I would make my own if the plane was close to me and mine. I have to ferry that plane here and the owner/seller just flew short local flights and never really needed the accuracy of the gauges. I tought / wish that someone had made some.

 

 

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Mistakes can be made Nev, and our Hornets and the Savs have a header tank with a low level warning light . The fuel is feed to the header tank from whichever wing tank( or neither if you forget to turn one on) and then onto the engine. I can remember two incidents, one were the PIC when changing tanks forgot to turn the second tank on and the second incident was when a fuel tank cap was left off and the fuel was sucked out. Simple mistakes. But you must admit another warning system can't be bad. With the AAK range the fuel can been seen (or not)running through glass fuel filters when you are warned to a system problem with the header tank low fuel warning light. You then have the time (with mine 15 minutes or 5 ltrs ) to rectify a mistake or find a landing place. Yes the low fuel warning light might be faulty but at least it has warned you to a problem. But you are right, you must know your fuel system. And yes it will not warn of a problem after the header tank, but Ole always fits fuel pressure gauges to his range so so if the engine pump fails we then have an electric pump to switch to. Still not foolproof but if you know your system, better than nothing.

As far as the Sav's I think they are set up similar, so maybe it is just a faulty sender unit. But don't just guess find out the problem and fix it.

Hi Re comment "With the AAK range the fuel can been seen (or not)running through glass fuel filters" Do you every get a small leak between the glass and the end piece (outlet end) that requires a slight tightening of the end pieces to stop the leak? I vae had this a coulpe of times. I also now carry a spare glass filter item. Just wondering if its a common leak situation with this type of filter. I like the fact you can see the fuel flow and any debris caught in the filter.

 

Regards

 

Mike

 

 

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Hi all,

is there any fuel gauge stick calibrated for the Savannah tanks that are available...or some measurements that I can duplicate.

 

thanks

Here's the measurements I use, they work well if the aircraft is levelish, courtesy of Barrie from Kiwiland.

 

Make a dipstick using these measurements.

 

Dip all tanks and add together as the levels can vary between tanks.

 

Cheers

 

Rick

 

savannah fuel calibration.pdf

 

savannah fuel calibration.pdf

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GREAT... just what I wanted ...although it says 38 lts max while the capacity is 36 ???thanks Rick

Mmmmm.

 

 

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