I replaced my fuel gauge sending unit with the Taiwan made aftermarket unit a few years back. Last year it stopped working and when I pulled it out I found that the float was full of gasoline. I emptied it and tried repairing it with JBWeld but a year later it is showing symptoms of the same problem.

According to cleanflametrap.com, this is a common problem but I haven't seen any recommendations for fixing it. I wish I would have kept my original sending unit as I would have just used the ball from it. The local junkyard doesn't have any sending units since the strip and crush all the gas tanks from the cars before putting them on the lot.

I saw a gas tank sealer product on the web from Caswell Inc. Anyone try using it to reseal a float?

Hi,

No I have not seen the product you site anywhere.
No I have not tried to repair plastic floats, per say, but have done one brass one from another car.
On brass you can use a little solder and very low heat to cut down on the expanding air inside. That was the trick on them.
At the factory they might use a evacuated chamber. Maybe held below atmospheric pressure a few inches of Hg.
The Taiwanese may be having the same issue of pressures or their nylon resins are out gassing in the injection molds leaving voids in the shell.

You might want to try a product from a Tru Value hardware store or maybe even Walmart. It is fairly popular.
It's called Seal-All in a red and yellow tube. It says on the package that it is "for oil and gasoline repairs." Don't ask how oil repairs are done of where to use it?

This might be worth a try as it is only a few dollars and readily available.
It does have a shelf life once its open of about a year so, you will want it find more uses for it.
It turns into more of a jelly and will not stick very well.

I would advise you to get the ball drained out first through its entry point or even drill the smallest hole you can. Maybe take a pin and open the hole a wee bit.
I would then encapsulate the whole shell in a coating of Seal-All and set the ball up on three needles stuck through some cardboard to let it dry.

This should work better than JB Weld as I'm not aware that their products are gasoline resistant epoxy mix. That stuff has a heavier body weight as its thicker.
I imagine Seal-All will be easier to work with. Keep it to a thin layer and continuous that way you will not be relying on adhesion to the plastic. Create a resin package for the ball.

Time will tell how it works, as before, huh?
Phil

I saw the Seal All at the hardware when I originally repaired it. Like JBWeld, it is gas and oil resistant - which means I don't have much faith in it holding up in the submersible environment that the float ball lives. The Carsten product I was referring to was intended to coat the inside of the gas tank so I expect that it is designed to be submersed.

For other options I have considered are floats designed for other cars that you can purchase for under ten bucks on ebay. They seem to be more cylindrical and I was concerned that they would hit the well in the volvo gas tank.

Hi,

I see your point on the Carsten product submersion but a minimum amount you would have to purchase would be overkill. I have price type of product and it a good deal over a new tank.

In years past, Seal- All was recommended for use to seal Welch plugs inside of carburetors to cover cross drilled points. The company was Tillotson Carburetors used on Harley-Davidison's and small engines on lots of lawn mowers today.
On those bikes they used a rubber diaphragm for a float control touching the inlet needle. The entire area under the plugs was immersed full time. The rubber would go bad but I never knew anything if the plugs leaked. I could see the film of Seal-All everytime I replaced the diaphragm though.

The Welch plugs are concave and fit an inside diameter and get flattened and the Seal is there to fill and cover the plug.
Very much like freeze plugs used in the sides of the red block for cooling jacket access.
I don't want is use in conjunction with freeze as an insurance policy to seal them.
Gasoline is thinner than water but does not have the same temperature extremes but they wanted a sealant on them. So it's a experience guess that it should work.

Seal-All has survived 50+ years doing something right? I think it's better than any shellac product that's been around longer. That era still has it places despite some high technologies hype, for lots more money. Most of it goes to the CEO's and shareholders. (:)

It's still your choice, Repair or Replace with another unknown" quality of float.

Phil