removing a rusting fuel sending unit

[sjy1954]

I just bought a used 1998 Bayliner Capri. The 1st thing I noticed is the gas gauge wasn't working. I opened the back up and found a wire on the fuel sending unit rusted off. I tried removing the (5) screws to the sending unit, but they are all completely rusted and wont budge. I scraped off the loose rust off and sprayed the screws with liquid wrench, but they still will not loosen.

The gas tank is a plastic built in gas tank.

I?m a little nervous about how to proceed, since I'm working on the gas tank.

Any suggestions on how to safely remove this rusty sending unit would be greatly appreciated.

 

[rcracerx]

Re: removing a rusting fuel sending unit

I just went through the same thing.

First thing I did was drain all of the fuel in the tank. Then I tried removing the screws but the heads snapped off. After the heads snapped off I was able to remove the sending unit from the tank leaving exposed the screws stuck in the tank threads. 3 of them I was able to get out using vice grips and wd-40. The other 2 I had to drill out. I took one of those umbrella things on a stick you would use in a fruity beach type drink and lowered it into the whole and opened it up. After I drilled out the bolts I closed the umbrella thing and removed it with the metal shavings that fell from drilling. I then took a long retractable magnet and stuck it in the tank fishing around for any extras. Bought a new gasket and screws from Boaters World.

Rc

 

[capt sam]

Re: removing a rusting fuel sending unit

lol...the umbrella trick is pretty good.

 

[sjy1954]

Re: removing a rusting fuel sending unit

Thanks for the response... So it sounds like brute force with vise grips is what you needed with a little coaxing with the drill.

What are the screws screwed in to? Is the plastic tank threaded or are there some kind of metal nuts attached to the plastic tank?

While I have the sending unit out, I am going to try and clean the tank as best as I can.

 

[capt sam]

Re: removing a rusting fuel sending unit

chances are they're just screwed into the plastic, maybe someone with a bayliner can respond. If so, it'll make it easier, just remember the umbrella trick, lol.

 

[rcracerx]

Re: removing a rusting fuel sending unit

My tank was made from alum so it had actual threads in the tank itself. I am not sure about a plastic tank. But all of the sending units and gasket kits that I saw when I was shopping for mine were threaded screws with out nuts so I can only assume yours is the same.

Yea the umbrella trick was actually the wifes idea. Just another reason I keep her around.

Rc

 

[Solittle]

Re: removing a rusting fuel sending unit

If the flange on the sending unit is metal and the screws go through the flange then the holes in the flange are most likely not threaded. Take a grinder and grind the heads off of the screws. The sender should lift off. You can then go after the screws with vice grips. Since the tank is plastic they should come out very easily.

 

[Mark42]

Re: removing a rusting fuel sending unit

The screws are most likely not just into plastic. They are probably in threaded inserts molded into the tank. I can't recall ever seeing a tank where screws were just run into the plastic.

Before drilling all the way through the inserts, I would try using a small "easy out" if you can find one. Soaking with Liquid Wrench will go a long way to loosening the screws.

If you do end up having to drill out the screw from the threaded insert, don't go all the way through the plastic at the bottom of the insert. Then get some stainless steel screws, washers and ny-lock nuts and cut the heads off the screws, and epoxy them into the inserts. After curing, the new sender can be installed over the new "studs" and tightened down with the washers and nylocks. And you won't have to worry about rusting screws again.

 

[Chris1956]

Re: removing a rusting fuel sending unit

Mark is likely correct about the plastic tank having moulded in steel threads to accept the fuel gauge. If you cannot salvage the threads, you may want to drill new holes in the plastic and tap them for screws. Now install the screws from the inside so the heads are inside the tank. Use nuts to hold on the sender.