I was cleaning the engine compartment on my 2004 F250 and discovered the positive battery terminal was covered with the powdery remains of corrosion. It was ok a couple of months ago when I I checked it last. I cleaned it up, the nut on the clamping bolt is almost gone. My guess is the seal must be bad on the positive terminal and a new battery is in order. What about the clamp? The starter wire is crimped into the battery clamp, is there a repair kit so I don't have to buy a new cable? Also, apart from losing the clock, will I cause any other problems disconnecting the battery? Thanks.

 

The battery might be OK - corrosion will build up on the + terminal if there is a bad or dirty connection between the clamp and the battery post.

I don't know about a repair kit, you're probably going to have to crimp another one on yourself or buy the entire cable. If it were me, I'd just buy a typical lead battery terminal clamp, cut off the old one, strip some insulation off, and clamp it down. It's probably a <$5 fix.

My 2001 is still going fine, it was sprayed (from the factory?) with a battery terminal protectant and there's no corrosion.

Seriously, it might not be a bad/leaky battery, more like normal corrosion from a dirty or bad connection.

 

Batteries will do this over time. It is not necessarily the seal. Most batteries have vents and slowly release gases.

The way to take care of this is to thoroughly clean the terminals with a wire brush terminal cleaner. Some terminal will have a strange dark oxide coat on them that kind of looks like dark plastic. This needs to be cleaned off. I use a battery terminal cleaner that has a flat blade or one that looks kind of like a reamer. I like the reamer but you have to be careful not to remove toomuch metal.

YOu should clean the battery top with a solution of water mized with Baking soda. THis will neutralize the acid on top of the battery. Be VERY CAREFUL you DON'T get this solution under the caps. You can also use a spray on battery cleaner.

I don't care for the spray on battery top protector. It leaves a sticky greasy film on top of the battery that supposedly prevents the acid buildup which drains the battery. But in my opinion it makes the top of the battery a mess to touch.

I prefer to use those little felt donuts that are soaked in the red goo baattery terminal protector. This seems to help prevent a bit of the corrosion you are seeing.

If you periodically wipe off the top of the battery and brush the terminals, the corrosion should not be a problem.

Good Luck,

Jim Henderson

 

I just use a little bit of oil from the dipstick on my terminals. A couple of drops will coat it and not let it corrode.

 

Glue a penny next to the terminal. The corrosion will go to the penny, not the post.

 

I will add that everything looked good a few months ago, and the powdery stuff I am refering to actually filled the inside of the red rubber cover over the terminal, and the clamp bolt is almost gone. The clamp itself is kind of a silver color when new, mine is bright copper color now.

 

It's copper color now because the acid stripped your plating off. There's no real worry there so long as you've got enough material left that it isn't brittle. Just make sure you protect it with grease or a corrosion preventer kit. I use both spray and donuts on my stuff. It's the first thing I do when I get a new vehicle.

As to your bolt problem, you can probably get a metric bolt to go in there if the rest of the terminal looks salvageable. I don't know the pitch and diameter off hand.

Are you gas or diesel? With the gassers, if you yank off the battery terminal you will lose your clock and your computer's memory. All that means is that it might not run its level best for a little while after you start it up after it's plugged back in. Now, if it's a diesel, it's got two batteries and so long as you didn't pull them both the other one will keep it all going for you. I think they remember radio presets these days, at least for a while.

 

Followup . . . .

- Rinsed to top of the battery with baking soda/water solution.
- Removed the clamp nut (at least what was left) with pliers and discarded the bolt
- Drilled out the hole to 1/4" and filed the square end to accept a larger 1/4"
carriage bolt
- Cleaned the positive post and inside of the clamp
- Installed felt donut
- Reinstalled clamp with new 1/4 carriage bolt
- Spayed protective coating on it

The clock and radio needed to be reset, I lost my trip miles, and all the gages went through a quick self test the first time I started the truck. If the engine/trans control computer is recalibrating, I can't feel any difference.

I will keep an eye on it to see if the problem recurs.

Thanks for the tips.