Tank sealer and fuel level sender

Looking for input about sealing up the fuel tank level sender. I did the left wing tank end cover today so perhaps asking this question just a tad late.

I gooded up the inside surface of the tank sender then the rubber gasket and the end of the tank. Found that as I made the bolts tight the gasket kept pushing out from under the sender flange. So anyway I stopped with the bolts at a point with uniform gasket showing around the whole edge of the sender. Here is a photo: Tank sealer on fuel level sender flange

Is this all that is needed to keep the sender attached and the tank not leaking?

For the main end cover on the tank I ditched the gasket altogether. Also I'm using stainless hex head bolts on these parts.

Thanks.

FWIW I used the cork gasket for the tank cover with a lot of proseal on both sides and ditched the rubber gasket for the sender and just used proseal on that. I lobbed a lot of proseal over the screws after the crews were tight. No leaks in over a year.

Roberta

Other tank

Hummm. Now I wonder if I should just not use the gasket on the other tank and do this one again without the gasket? I'll probably test it for leaks after everything is fully cured and make a decision.

Thanks

tank sealer

I installed the senders with the rubber seals and finished them up with sealant on the outside similar to your picture. The left one leaked through two screw holes. I replaced the left one and on the second attempt, I used sealant on/in the screw holes and a little under the rubber gasket all the way around. It is holding so far. My limited experience tells me that sealant on the outside provides very limited protection. Good Luck

I tossed the rubber seals and went the ProSeal route after I noticed the screw callouts with the rubber seal were not sufficient (at least to my satisfaction).


When I did the right tank a few months ago I had to get in to the access panel again (I didn't use the gasket on the access cover either) and it's amazing that anything can leak thought that setup (I was trying to get access to a leak along the baffle. ) Man, it was tough.

Proseal ONLY!

Van's recommended that I throw away the cork gasket AND the rubber gasket for the float sender and use proseal ONLY on both surfaces and around each of the screw heads.

That's what I did and don't have any leaks (so far...)

Jack

RV-7A flying...
N174JL
www.jacklockamy.com

There are no new problems...

Resurecting an old thread....

I went out to the hangar to do some finishing work this morning, and as soon as I opened the door, got that faint sweet smell of 100LL...damn! Yup, a thin blue stain on the bottom of the wing showed a leak under the wing root fairing. Fortunately, those are just clecoed on right now, so pulling it was easy, and sure enough - the fuel level sender is leaking. Or, rather, the screws holding the fuel level sender were leaking, becasue I didn't seal them with pro-seal....

I did call Van's about the gaskets, because they seemed to have gotten kind of squishy. Bruce recomended getting new ones at the auto parts store...he didn't recomend leaving them off. Can I get an idea how many folks have gone with pro-seal only? I did the tank access covers with pro-seal only, and ditched the cork gaskets. I used the sender gaskets cause I figured they had more likelihood of being removed.

BTW, the auto parts stores were useless when I asked for a standard five-hole Stewart Warner gasket...even when I showed it to them. If you don't have a make, model, and year of (ground) vehicle - forget it!


Paul Dye

Proseal only

Sorry to hear about the leak. I used proseal only on both the sender and the plate. I tested with air pressure for several days and didn't get any leaks. I have not yet put fuel in the tanks, tho. Perhaps now is the time for me to fill them with fuel, while they are not yet mounted to the fuselage.

As a side note, it's interesting how depending on who you talk to at Van's you get a different answer. I just keep calling until I get the answer I want!

rv8ch said:

As a side note, its interesting how depending on who you talk to at Van's you get a different answer. I just keep calling until I get the answer I want!

Click to expand...

I stopped calling -- and writing -- Van's altogether. Too much chance I'll run into a certain English major there who seems to specialize in flippant answers designed to make you feel stupid while giving insufficient information to extract help.

When you think about it, each of those guys has built -- mostly --- one plane. Despite this same English major's constant attempt to minimize the value of RV information on the Internet, the collective wisdom, education and experience of the folks here who have built is unmatched, imho.

You get different answers here too. But at least they're mostly thoughtful and insightful.

Fuel sender sealing find..

Here's something I found that I'm using on my RV-10. I'm concerned about pro-sealing in the senders, if they go bad, removal and replacement will be quite a challenge: at that point you can't really fully seal in the replacements. So from the get-go I was looking for a solution that would make the senders replaceable. I think the fundamental issue is leaking from under the screw heads if the proper rubber gasket is used under sender flange. Well, I found in McMaster-Carr, a stainless steel machine screw with a built in silcone O-ring under the head. The bolt head has a machined groove so the O-ring just barely compresses when the bolt is torqued down.

part #90825A919

You should note that the o-rings that come on those screws are made of silicone and are not very resistant to fuel. They should be changed to viton to ensure that they don't break down.

An alternative to Pro-Seal is to use an access panel sealant. Similar to Pro-Seal but less adhesive and is designed to be removable.

Thanks for advice. I was thinking about those o-rings and that I need to check the material compatiblity, I'll post the o-ring part # in Viton.

RV-10 wings almost done


thanks
bob