Fuel sender replacement issue

[SeaVee]

All,

Just replaced the senders on my two tanks in my 2001 265. The Aux tank sender was original and the replacement went in with no problems. The main tank sender was not original. I had a bear of a time with one of the bolts and ended up pulling the threaded insert out of the tank with the bolt. So now I have no way of getting it tight and it’s leaking fuel.Has anyone had this problem? Pic below

 

[johnt2032]

Just about to do the main tank sender on my 2000 265. What is the depth of the tank? Hope someone has a solution of I end up with the same problem

 

[Punch53]

This is what was used.

Rivet Nut | Rivnut® | Bollhoff Rivnut® |

Rivet Nut USA is a Bollhoff Rivnut®, or rivet nut, distributor that offers low, medium and high volume quoting options for a wide variety of applications.

www.rivetnutusa.com

 

[luckydude]

Hey OP,

Not sure what the issue is that you are having, but here is something I have learned. This was on my previous boat, a Triumph but someone said they are all like this. The holes are not evenly spaced, there is only one way they go back together. In the Triumph, the wires were at (I think) 3 oclock if forward is 12.

Color me surprised, how hard is it to make the holes evenly spaced?

Does anyone know if that is a generic sender thing or was Triumph just being weird?

 

[SkunkBoat]

This is what was used.

Rivet Nut | Rivnut® | Bollhoff Rivnut® |

Rivet Nut USA is a Bollhoff Rivnut®, or rivet nut, distributor that offers low, medium and high volume quoting options for a wide variety of applications.

www.rivetnutusa.com

wow, not to side track the thread but those are what they used on the dash as threaded inserts in the fiberglass for the switch/dash panels. Wish I could find 4 of them easily

EDIT: Hmmm..... now that I know the name Rivnut, they are all over ebay/amazon/hrbor freight! THANK YOU!!!!


my tanks were replaced in 2017 and they welded in a thread for a threaded WEMA sending unit....no screws!

 

[seasick]

The problem with the rivnut is that the installation tool is designed to be used on the flange side of the insert. In the case here, that would be from the inside of the tank and that's a problem. My thought is to buy some appropriately sized rivnuts in aluminum, Grind off the narrow end so that the length below the flange is equal to the thickness of the tank material. Apply an adhesive rated for gasoline around the rivnut flange and carefully insert from inside the tank. Using a proper sized bolt and a spacer ( washers will do, tighten the insert by tightening the screw and let sit till the adhesive dries. Hopefully when it dries it will have adhered well enough to the inside of the tank to allow the sender to be bolted on.
A second approach would be to get inserts with the serated shaft. You will need the hole to be a bit smaller than that diameter. Set the insert using a channel lock pliers or maybe a vicegrip . Hopefully it will bite. In this second example, you still need to grind the lip to match the thickness of the tank. That should be done away from the tank

The third and maybe easiest to do but not the prettiest is to 'glue' in a bolt from underneath. It will need a wide head or a wide washer that is also glued to the head of the bolt. The sender flange will not be slid over the bolts and attached with nuts and washers
In the adhesive examples, you can use a gas compatible epoxy such as

Amazon.com: J-B Weld 8217 TankWeld Gas Tank Repair - 1 oz.: Automotive

Buy J-B Weld 8217 TankWeld Gas Tank Repair - 1 oz.: Soldering Flux - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Punch53]

The flange goes outside the tank according to all that I've read.

 

[seasick]

That is what you would normally do but it leaves the lip of the rivnut proud of the tank. The gasket wont seal. If you look at the photos posted, you can see that the threaded inserts were pressed in from underneath

 

[SkunkBoat]

The problem with the rivnut is that the installation tool is designed to be used on the flange side of the insert. In the case here, that would be from the inside of the tank and that's a problem. My thought is to buy some appropriately sized rivnuts in aluminum, Grind off the narrow end so that the length below the flange is equal to the thickness of the tank material. Apply an adhesive rated for gasoline around the rivnut flange and carefully insert from inside the tank. Using a proper sized bolt and a spacer ( washers will do, tighten the insert by tightening the screw and let sit till the adhesive dries. Hopefully when it dries it will have adhered well enough to the inside of the tank to allow the sender to be bolted on.
A second approach would be to get inserts with the serated shaft. You will need the hole to be a bit smaller than that diameter. Set the insert using a channel lock pliers or maybe a vicegrip . Hopefully it will bite. In this second example, you still need to grind the lip to match the thickness of the tank. That should be done away from the tank

The third and maybe easiest to do but not the prettiest is to 'glue' in a bolt from underneath. It will need a wide head or a wide washer that is also glued to the head of the bolt. The sender flange will not be slid over the bolts and attached with nuts and washers
In the adhesive examples, you can use a gas compatible epoxy such as

Amazon.com: J-B Weld 8217 TankWeld Gas Tank Repair - 1 oz.: Automotive

Buy J-B Weld 8217 TankWeld Gas Tank Repair - 1 oz.: Soldering Flux - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I don't follow you. I don't see why the thread can't stick down into the tank. Am I missing something?

they did use the thin flange version so the top is nearly flush.

 

[SeaVee]

Spoke to the tank Mfr this morning, RDS Manufacturing. They did use these Rivnuts when my tank was made (2001) but don’t use them now. They recommended to rotate the sender 180 and drive a new set of holes. Problem is, I got 130 gallons of fuel in there! They said try a Air drill or hand drill. Second recommendation was a plate and split ring like was posted here previously.

 

[wspitler]

Agree with seasick. Maybe a thick custom made gasket would work, but clearly not ideal. That is a prime location for differential metal corrosion. I use a corrosion control thread lubricant such as molykote to minimize corrosion when I see aluminum against steel. I may pull mine a re-coat the machine screws to avoid future problems.

 

[SkunkBoat]

Hey OP,

Not sure what the issue is that you are having, but here is something I have learned. This was on my previous boat, a Triumph but someone said they are all like this. The holes are not evenly spaced, there is only one way they go back together. In the Triumph, the wires were at (I think) 3 oclock if forward is 12.

Color me surprised, how hard is it to make the holes evenly spaced?

Does anyone know if that is a generic sender thing or was Triumph just being weird?

they are never evenly spaced. It only goes on one way.

 

[seasick]

Spoke to the tank Mfr this morning, RDS Manufacturing. They did use these Rivnuts when my tank was made (2001) but don’t use them now. They recommended to rotate the sender 180 and drive a new set of holes. Problem is, I got 130 gallons of fuel in there! They said try a Air drill or hand drill. Second recommendation was a plate and split ring like was posted here previously.

The aluminum tank won't create sparks if drilled with a manual drill (remember those?)
Of course if using bolts, the holes will have to be tapped which will cause metal filings to be created and some way to block them from getting into the gas would be prudent
I think all that would scare me. I am leaning towards the epoxied inserts. Just use a gasket as an alignment jig.

 

[luckydude]

The aluminum tank won't create sparks if drilled with a manual drill (remember those?)
Of course if using bolts, the holes will have to be tapped which will cause metal filings to be created and some way to block them from getting into the gas would be prudent
I think all that would scare me. I am leaning towards the epoxied inserts. Just use a gasket as an alignment jig.

The engineer in me is trying to imagine some way to get something in there to catch the shavings. And also you have the water separator and the fuel filter, but still, shavings in gas kinda bugs me.

So I would get some 55 gallon drums, the steel ones, make sure whatever was in there before is something you can safely wash out, pressure washer with soap, do a nice job and get them clean. Dry them out and siphon out the gas. I have 3 of these that I store diesel (I have two tractors and an excavator). They work well.

It's a pain in the ass but so is shavings in the gas. Anyone have a better idea?

 

[seasick]

That is why the epoxy method would be my choice.
I suppose that you could get a 1 foot or so square piece of plastic sheet material and manage to unfold it inside the tank with a piece of line to keep it from floating away. That would catch any shavings.

As to emptying the tank, gas fumes are extremely dangerous and a partially/'empty' tank can be a bomb.. A full tank as crazy as it sounds is less explosive. The proper method to work on gas tanks is to drain the gas and fill the tank with water to displace the vapors. If I remember correctly another method is to drain the tank and add dry ice. That freezes the vapors. Regardless, before working, remove all possible spark sources.

 

[luckydude]

That is why the epoxy method would be my choice.
I suppose that you could get a 1 foot or so square piece of plastic sheet material and manage to unfold it inside the tank with a piece of line to keep it from floating away. That would catch any shavings.

As to emptying the tank, gas fumes are extremely dangerous and a partially/'empty' tank can be a bomb.. A full tank as crazy as it sounds is less explosive. The proper method to work on gas tanks is to drain the gas and fill the tank with water to displace the vapors. If I remember correctly another method is to drain the tank and add dry ice. That freezes the vapors. Regardless, before working, remove all possible spark sources.

I was thinking more a can with a stick tie wrapped/taped to the side. Stick it through the hole and then under where you are drilling. Tricky.

Gas has to be hot to vaporize and it needs to be a vapor to explode. That's what a carb does, turns it into a mist and mixes it with air. I may just have gotten lucky but I drained the gas tank on my Triumph with no drama. I definitely agree you don't want sparks but I think it is less of a concern so long as it isn't a really hot day.

That said, if whoever is doing this isn't comfortable with what they are doing, get someone with experience to help or do it. I'm very do it yourself and I find myself paying for some stuff. It's fine.

 

[seasick]

Hopefully your moniker 'Luckydude' stays with you!
Many years ago when I worked in a gas station, one of the mechanics had sent out a gas tank with a leak to be soldered. It came back and looked fine but it turned out it still had a small crack. Since the tank was empty and had been filled with water at the radiator/tank shop, the mechanic assumed it was safe to do a quick repair. So he grabbed the soldering torch and some solder and started to repair the leak. There a was a gigantic kaboom. Other ran into the work room and the mechanic was unharmed but in shock. The tank was missing. It was found across the street and instead of being flat and rectangular it was big and round and all the groves from the stamping at the factory were smooth. Fortunately it stayed in one piece but it could have killed the mechanic.Lesson learned.

 

[seasick]

There was an episode on Mythbusters years ago about whether gas tanks with leaks would explode like they do in the movies.
They had a heck of a time trying to get a tank in a car to explode. It was only explosive when it was just about empty.

 

[wrxhoon]

My understanding is you only have one hole without any thread for the screw to bite onto. If I was you I would use a small piece of 3/8" aluminum tap the correct thread then use some kind of epoxy/glue whatever that is fuel resistant and fix it on the inside of the tank. No drilling at all, the only problem, you have to take care so you don't drop any crap in the tank.
Seasick is correct, a full tank will not ignite easy , empty tank full of vapor is like a bomb.
Make sure you don't use any power tools that are electric, if you must grind or drill use compressed air tools or hand tools.

 

[SeaVee]

So- I have a great guy that has been helping me getting this boat squared away, and he is very adverse to drilling. He has worked extensively with the rivnuts and he has talked me into trying those before we do anything else. I’ll keep everyone posted on our progress. Going to order parts today.