Fuel gauge removal

[8424]

Hi George.

I have AS&S open buying bolts, so I looked up the gasket:

https://www.aircraftspruce.com/catalog/pnpages/15-4.php

I went to the gauge first and the gasket is listed as an accessory along with the float.

Gauge:

https://www.aircraftspruce.com/catalog/ ... _gauge.php

I haven't purchased/installed this gasket, but it is the part number Mac gave us.

Hope this helps.

Steve A H

[2066]

Here y'are. Actually, the one I removed (Right) appeared to be wrong one (a bit too wide), 'though had been there for many years with no leaks. The 15-4 fits and works perfectly. It's good to get one that's as fresh as possible when reinstalling & Spruce does claim to "rotate their stock". Mac

IMG_8340.JPG (458.95 KiB) Viewed 2009 times

[8296]

I guess I can infer here that it might be best to replace the whole gauge assembly and go with a Rochester. They are not prohibitively expensive. I noticed in Mac's picture what looks like what might be some rust at the root of the pictured float. If I chose to go "this route"after I pull the fuel gauges but find them unsuitable (I am pulling both tanks for fuel neck repairs) to refurbish and return to an airworthy condition, any idea about where you set the float on the Rochester?

George

[2066]

I guess I can infer here that it might be best to replace the whole gauge assembly and go with a Rochester. They are not prohibitively expensive. I noticed in Mac's picture what looks like what might be some rust at the root of the pictured float. If I chose to go "this route"after I pull the fuel gauges but find them unsuitable (I am pulling both tanks for fuel neck repairs) to refurbish and return to an airworthy condition, any idea about where you set the float on the Rochester?

George

There's a bit of difference 'twixt the gauges. The new one will come with a long, straight float pivot rod that has to be cut and bent to function at "full" and at "empty". It's a little tricky, but can be done. Were it not for the difference in length of the assembly (from gauge back to float pivot) you could just put new next to the old and "copy"...but as best I recall, that won't work. I'm aware of one of the fleet with a Rochester installed that had the pivot/float rod cut too short...so, it only registers from 1/4 empty to 3/4 full &, of course, that isn't "legal". Maybe there's someone out there who has cut/bent a new Rochester to function perfectly and they'll share the length and bend specs(?). "Nothing difficult is ever easy"

[6597]

Here's a shot from an original gauge to show the length of the rod, the newer Rochesters are definitely too long.

[6643]

it only registers from 1/4 empty to 3/4 full &, of course, that isn't "legal".

But, if you bend it so it says "Empty" when the tank is empty, then it's "legal". Nothing else matters, as long as it doesn't say "full" when it's not full.

[8296]

I think there is one final word of caution in screwing back on the gas gauge that Lorraine Morris wrote about back in the June/July 2011 paper edition newsletter

"The general consensus is that there were two gaskets used originally in the fuel gauge installation. One of them is a round gasket that has a lip which fits against the gas tank and gauge and the other gasket is square and fills the space between the back of the gauge and the square gas tank lip. The parts manual, however, doesn't show these. So when somebody pulls the gauge and replaces just the round gasket (because it is leaking - my comment), there is no support behind the screws that hold the gauge in place. When the the leak (behind the gauge - my comment) starts, and they tighten down the screws, the gauge gets cracked. . . . .Be sure you don't crank down on the gas tank corner screws too hard that you crack the gauges"

Her word of caution is very pertinent as Mac's suggestion is to purchase and use a round gasket.