Fuel Gauges

[submoa]

George,

Hey guys, FNG here and just bounced in on this old thread. Hope it's not too old.

I understand exactly where you are coming from on the gauges. I bought the same gauges for my 1954 180. The "reach" of the guage is too short and no matter how you bend, cut or try to adjust the arm, it will not allow full travel of the arm inside the tank. You are absolutely correct about the gear ratio. It is different and if the arm is cut to the length ( has to be short) to allow it to indicate properly, the float hits one of the screw bosses on the inside of the bladder, and it will never go all the way to empty. I believe that the gauges of this type for the Cessna are probably all the same and that the actual quantity of the tank is not important. It's the total depth of the tank that's critical to proper indication. These gauges do not read in total agllons, but fuel remaining relative to total capacity, whatever that may be. Both the original factory guage and the Spruce Replacement use a magnetic coupler. The problem I have with the old guages and I think it's the common problem, is hat the magnets start to lose their magic, and do not effectively hold whatever piece inside the gauge it's supposed to hold onto. This allows the darned things to bounce all over. I tried to remagnatize one of my old guages and had a little success---but it was short lived. If whomever has that flyer from Rodchester or Scott, can send it to me I'd like to see it. Thanks Much Gang!!

[GAHorn]

submoa,... again, we may be talking apples-to-oranges. YOu don't specify exactly which model gauge you found difficulty with. Making the statement that you bought the "same gauge" .....doesn't mean that is so. What you probably meant was that you bought a mechanical float type gauge that was similar and had issues when installed in your Cessna 180 aircraft. Again,....not the same scenario.

The "flyer" issued by Scott/Rochester is in my personal library at home. I'll try to locate it and scan it into this discussion when I get home....in 3 weeks.

[submoa]

Gahorn,

No, my friend we are not talking apples and oranges. Spruce only has one apple in that bin and it is part number 05-16700. It fits beautifully to the mounting flange, but has a shorter reach than the original gauge. It comes with a float arm that is cuttable/bendable to any length you want, and is marked with the correct limits on the dial. It is almost identical to the factory part # 7083-00022 ($430.00) except the Cessna part comes with the float arm already cut to length. I have both sitting on my bench, and they both have the same issues. When the arm is cut to the correct length, to allow full deflection of the arm from top to bottom, ( 180 degrees) the float will not fully deflect to the top or bottom positions due to interference with the screw bosses on the inside of the bladder. These bosses are the backside of the flange mounting bolts on the outside of the bladder. This happens because the "reach" of the guage does not allow it to extend far enough into the bladder and allow the float to travel it's entire range. This may be a 180 issue only, or it may be a "my airplane" issue, but I'm sure others have encountered the same problem. I live about two blocks from Spruce and I have been in there many times trying to resolve this. Chad at the will call counter, is tired of looking at me and my fuel gauges.

[GAHorn]

Well, just to "belabor" the point..., until you clarified the exact PN gauge you utilized...we possibly were/ARE still talking apples/oranges.
Since WE (170 owners) do not have a "bladder" with flange-mounting like your 180 does....it's apples/oranges.
Also, since we 170 owners have a different depth tank...it's apples/oranges. (Our metal tanks do not have their filler-caps in the same position as your bladder does.)
And then, since the Rochester gauge mentioned in the specified flyer is a 5000 series...and Spruce sells a 7000 series... it's also apples/oranges.
I'm not looking for an argument, I'm only saying that until we specify part numbers ...then we MAY be talking apples/oranges. Now that you've clarified exactly which PN with which you're finding difficulty, it will be easier to avoid that problem.

Anyway... as a possible solution....it may be possible to alter your operating/float-arm by bending 90-degrees to the angle-of-motion, thereby allowing full movement in an area fwd or aft of the flange mount bolts? (In other words...instead of shortening an arm...simply bend it fwd or aft 90-degrees. The float will still operate through it's full range..but will do so in an "offset" position...which may solve the issue.

[Bruce Fenstermacher]

Until recently, without first hand experience working with these gauges, thought what could be so difficult making a few bends a and slight mods to get them to work perfectly.

Then I tried to make one work in a Luscombe tank. It's not so easy. I learned a lot about the way they work and don't work. Never did get it to work right in the Luscombe and sure do understand why you may not get them to work in Cessna tank.

[submoa]

Gahorn,

We 170 owners, as you put it, understand. I do also own a 170, and an 0-1, and a Stearman (under restoration at the moment). So---is it okay if I stay?? I promise not to mention any other airplane.

[Bruce Fenstermacher]

Gahorn,

We 170 owners, as you put it, understand. I do also own a 170, and an 0-1, and a Stearman (under restoration at the moment). So---is it okay if I stay?? I promise not to mention any other airplane.

No it's not Ok. While we focus on the 170 it is not acceptable if you don't tell us about your other aircraft (of course another thread would be appropriate). And we expect pictures.

[submoa]

Thanks Bruce. Will do.

[ralphyoung]

New guy, so bear with me, my 48 170 came with a brand new fuel gauge that is kept behind the seat. It looks a lot like a paint stir stick and is marked on one side for right tank and the other side for left tank. Seems to work. I did an N number search and two prior owners did not know how to use it.

[Bruce Fenstermacher]

Ralph,

If you have a stock 48 then you will have two gas tanks on left side and one gas tank on the right side, you will have one gauge for the left two tanks and one gauge for the right tank. The gauges for each wing or marked the same that means that when you're reading the left tank which has twice as much fuel a half tank will have twice as much fuel as the right tank does when it's reading half.

The gauges in all 170s bounce when their new they bounce when they're old. Some bounce more than others but for the most part all of them are hard to read accurately. So many people make up a stick they used to dip their tanks when they fill them. These sticks of course have to be calibrated. What you need to do is empty your tanks and then start filling them up and stop at increments and stick the tank and market it so it is marked accurately. When sticking your tank it is important to note exactly how you put the stick in the tank and repeat that exact position each time for the best accuracy. Again as noted earlier if you have a stock 48, when sticking the left tank the reading will be twice as much fuel as the same mark on the right tank. In fact it would be best to have two different sticks one for the right and one for the left or at least have two different sets of marks one for the left tank and one for the right. If you do find however that you have to tanks on both sides of your 48, this is a popular modification. Then one stick should work for both sides.

The Plexiglas dip stick that Aryana showed in his post is a popular stick. As mentioned you can buy these already calibrated for certain aircraft however there is none calibrated for the 170 so you must buy their universal stick and then recalibrate yourself by cutting the end off making the gallon marks levels match up to you are actual tank level. If you find one of these and buy it fine I'm sure you will be happy with it. However a regular stick such as an old yard stick marked with a marker can work just as well and in fact sometimes even better.

[N2255D]

Here is what I used and it cost next to nothing. Has to be calibrated either way. http://www.aircraftspruce.com/catalog/m ... yltube.php

[ghostflyer]

I had to replace my fuel gauges as they were doing a continuous fuel drain for me in the wrong place. The spruce type were fitted. After many hours it was found that bending the float arm 90degs only produces more problems.if in a tail down or nose up situation on the ground or in flight the error is magnified. So the short arm is the only way. However the dip stick method is the best method plus a EI fuel computer was added to give me fuel flow and fuel used . I have got to know what fuel flows my engine likes and at what EGT and CHT to run .

[Bruce Fenstermacher]

I had to replace my fuel gauges as they were doing a continuous fuel drain for me in the wrong place.

Could you elaborate? Besides the gasket under the flange of the gauge, they can not leak.

[blueldr]

Trying to keep track of your fuel? Install a SHADIN inrument. They're uncanny accurate!

[FredMa]

SHADIN inrument? what's that? I'm surprised you didnt recommend a FREE paint mixing stick from home depot.