Any way to fix leaky battery post?

[oil pan 4]

Usually I just replace the leaker with an AGM, problem solved -$200 or more.
Usually when they leak this bad they're near end of their useful life any....
I've got a flooded group 65 (bigger and expensiver) battery in my ford that tests pretty good but it just leaks. I can probably get another year or 2 out of it aside from the leaking.
As far as achieving the means to an end I'm not afraid of electricity, battery acid or melting lead, more afraid of spending $269 not including tax to replace a serviceable but messy battery with a sweet AGM.
The way I figure it I'm probably in it for a new battery, saving this one can be an experiment, even if it fails.

Has anyone ever tired:
Super glue?
RTV?
Cutting off and recasting the post to stop a leak?
It doesn't have to last a real long time, even a few months would be a success.

 

[walterjay]

I would use an epoxy. You have nothing to lose.

 

[doitmyself]

You could also install those battery felt protectors and change them as needed to retain the battery in service. Maybe double them up.

 

[oil pan 4]

You could also install those battery felt protectors and change them as needed to retain the battery in service. Maybe double them up.
View attachment 290326

Yeah those are okay. I was more interested in keeping the acid inside the battery.

 

[doitmyself]

A Google search claims that epoxy will form a mechanical bond with lead. If attempting the epoxy, I would get the plastic and lead super clean and use coarse sandpaper to get a good rough surface to enhance the bond.

 

[walterjay]

I recommend Gorilla Clear Epoxy for that application. It seems to have just a little bit of flexibility to it when cured.

 

[toad]

Usually I just replace the leaker with an AGM, problem solved -$200 or more.
Usually when they leak this bad they're near end of their useful life any....
I've got a flooded group 65 (bigger and expensiver) battery in my ford that tests pretty good but it just leaks. I can probably get another year or 2 out of it aside from the leaking.
As far as achieving the means to an end I'm not afraid of electricity, battery acid or melting lead, more afraid of spending $269 not including tax to replace a serviceable but messy battery with a sweet AGM.
The way I figure it I'm probably in it for a new battery, saving this one can be an experiment, even if it fails.

Has anyone ever tired:
Super glue?
RTV?
Cutting off and recasting the post to stop a leak?
It doesn't have to last a real long time, even a few months would be a success.
View attachment 290325

I've repaired two batteries with leaking post seals using epoxy. They both kept the seal until the batteries were replaced, one for 4 years and the other for 2 years. Clean the area well with a toothbrush and baking soda, then rinse well, dry well, rough up the plastic and polish the lead with sandpaper,and apply the epoxy. I went slightly up the post with the epoxy, maybe 1/8 ". I should add that my batteries were not in quite as bad shape as yours. Good luck!

 

[Donald]

Is it an Exide battery?

Time for a new battery clamp also. Cut the insulation back a little to check for hidden corrosion.

Some people loosen the battery clamp and try and twist it off. You typically can do that a tiny bit but if a tiny bit of twisting does not do it then you need a battery clamp puller. Like a tiny gear puller.

If you twist the post you break the seal and you minds well label the battery Exide as it will be a leaker.

 

[WobblyElvis]

Clean well and use nail polish. Comes it's own applicator brush. Choice of color is up to you.

 

[SC Maintenance]

Coat around where the post exits liberally with some sticky grease - like tacky red - then use the little felt pads mentioned. Double stack them if you have enough post. Best I found so far.

 

[oil pan 4]

Is it an Exide battery?

Time for a new battery clamp also. Cut the insulation back a little to check for hidden corrosion.

Some people loosen the battery clamp and try and twist it off. You typically can do that a tiny bit but if a tiny bit of twisting does not do it then you need a battery clamp puller. Like a tiny gear puller.

If you twist the post you break the seal and you minds well label the battery Exide as it will be a leaker.

I used a battery terminal puller. I didn't have one so I bought one for $25.
I cut off that cheap factory S off there and crimped on some ring terminals. Connected the ring terminals naval style battery connectors on both the + and - sides.

 

[Donald]

I used a battery terminal puller. I didn't have one so I bought one for $25.
I cut off that cheap factory S off there and crimped on some ring terminals. Connected the ring terminals naval style battery connectors on both the + and - sides.

Well aside from the future leaking you should be good to go. You can try and seal it with some product.

3M 5200 marine sealant.

You can email JB Weld, they will answer quickly.

And even if sealed with a product of your choice felt washers are cheap.

 

[football]

No need for an almost $300 battery. I’d replace it under warranty if it still has a warranty or just swap it out for an $79 Walmart special.

And yeah the battery cable needs replaced.

Drown the battery post in dielectric grease and much less likely to have that kind of corrosion in the future.

 

[JimPghPA]

My go-to epoxy for difficult applications is the loctite EA E-20 HP, EA E-60 HP, and EA E-NS HP. It's one of the strongest line of epoxies made and sticks to almost everything except silicon and slippery plastics. It holds up when exposed to most chemicals.

E-20 is easy to use. It has about a 20 minute working time. It grips to almost everything very well.

E-60 has about a 60 minute worhing time, it is very thin and can run before it sets, it is slightly stronger than E-20

E-NS means no sag, and it does not run.

For the battery post, I would use E-20.

McMaster-Carr sells it, and the gun required to dispense it.

I usually dispense what's required onto a piece of thick paper with a glos finish so little is lost into the paper. The kind of paper from some packages works well.

Only use the mixing nozzles if you require a lot and you don't mind the cost of the nozzle ( it a one use item ) and the loss of epoxy in the nozzle.

Be sure to mark one side of the removable cartridge cap with a black sharpie and then the side of the cartridge that black aligns with after you turn it 90 degrees, so you don't mix the removable cap sides with the wrong cartridge side.

Besides the high price, these epoxies have a limited shelf life of around 6 months +/- some. But they work so well that I keep a cartridge of E-20 always around.

 

[oil pan 4]

No need for an almost $300 battery. I’d replace it under warranty if it still has a warranty or just swap it out for an $79 Walmart special.

And yeah the battery cable needs replaced.

Drown the battery post in dielectric grease and much less likely to have that kind of corrosion in the future.

Already done. Here's what I did on my dodge last year. The Ford looks exactly the same, just add some leaked acid.

Post in thread '1999 dodge Dakota battery replacement (resolved)'

Jun 24, 2025

Still doing work.
In nearly 30 years of messing around with car batteries and doing it almost daily for around 20 years I would say crimped ring terminals and naval style lugs are the way to go.
But I'm also lazy and I'm not about to cut off perfectly serviceable and corrosion free battery connectors.

• oil pan 4

• 

 

[oil pan 4]

My go-to epoxy for difficult applications is the loctite EA E-20 HP, EA E-60 HP, and EA E-NS HP. It's one of the strongest line of epoxies made and sticks to almost everything except silicon and slippery plastics. It holds up when exposed to most chemicals.

E-20 is easy to use. It has about a 20 minute working time. It grips to almost everything very well.

E-60 has about a 60 minute worhing time, it is very thin and can run before it sets, it is slightly stronger than E-20

E-NS means no sag, and it does not run.

For the battery post, I would use E-20.

McMaster-Carr sells it, and the gun required to dispense it.

I usually dispense what's required onto a piece of thick paper with a glos finish so little is lost into the paper. The kind of paper from some packages works well.

Only use the mixing nozzles if you require a lot and you don't mind the cost of the nozzle ( it a one use item ) and the loss of epoxy in the nozzle.

Be sure to mark one side of the removable cartridge cap with a black sharpie and then the side of the cartridge that black aligns with after you turn it 90 degrees, so you don't mix the removable cap sides with the wrong cartridge side.

Besides the high price, these epoxies have a limited shelf life of around 6 months +/- some. But they work so well that I keep a cartridge of E-20 always around.

Normally I go with the longest working time I can stand. One of my go to epoxys is west systems 24hr. It's about 20 years old and still seems like it works good as new.
Walterjay recommend gorilla glue epoxy, says it has a little bit of flex to it. A little bit of flex is good, thats why I was thinking RTV and that's the reason I'll use rtv over epoxy Ina lot of things, that flex rtv provides helps a lot. When most epoxys flex they crumble or crack loose.