Corrosion Issues... cures?

[REZARF]

I have cleaned my terminals on my 100 3 times in the past 8 months.... they keep looking like this. I have some pretty severe corrosion on the radiator support, under the battery tray and some of the battery hold down has been eaten away. This had been obviously going on for some time before I owned the cruiser.

I have treated the paint and sealed it up. I have cleaned and used dielectric grease, battery post terminal coatings, felt washers under the contacts etc.

I am about to tear the Toyota Factory terminal off and wire each of the main primary wires directly into an audio style terminal that accepts heavy gauge wires. However, I need to figure out why I am getting corrosion in the first place.

Charge holds steady at 13.5-14v while driving, and my battery is good. I have read that dissimilar metals can cause the corrosion and flooded batteries can too with some caustic vapors coming off the battery. FWIW, I am primarily getting 90% of the corrosion or more on the positive post only. I think I remember that means an over charge of some sort?

Any help would be greatly appreciated at getting to the source and not just band-aiding it again.

The underside.

 

[Get outside]

I have the same problem with our Honda! I cleaned the thing up so many times and months later is back again!!! I'm all ears to a possible solution.

 

[LBridges]

Two possibilities I experienced back when I worked as a mechanic... and then one stopgap fix (maybe).

Since the pics you provided seem to imply (to me anyway) the corrosion is starting at the bottom of the battery terminal, I suggest the seal where the post physically enters the battery housing is bad. When the battery is charged a slow release of corrosive fumes is bathing the terminal. The only way I know to fix that is to replace the battery. Normally caused by someone twisting a fully tightened terminal.

If it really isn't coming from the bottom first, then the next most common cause is an alternator system that is overcharging.

I have seen cases where greasing up the terminal just makes wires terminals corroded elsewhere - like the starter terminals, body ground, etc. And due to the service friendly location of the starter on the 100 (that's being facetious if not obvious), that is not a place you want corrosion. So I personally would never grease up a terminal, but I do use those little green & red felt circles (really no idea why, I just do). I don't grease up the battery terminals because I like to see issues in easy to fix places.

Never tried, so I can't verify, but I was told once that a stopgap measure was to use some electrical sacrificial element next to the terminal, sort of like a zinc ball sometimes used on a house's exterior ground wire. This might be a penny glued down to the battery top and touching the terminal. Maybe somebody more electrically sophisticated can suggest something better than a penny or maybe that's already an optimum. I don't know and can't even verify

 

[Sandroad]

Yuck. Couple things. First, the positive post terminal in the photo is not like my OEM terminal. Is it possible yours was replaced with a cheap one that's causing the corrosion with incompatible metal? Maybe yours is OEM for that year? Second, I'd replace the battery and the terminals. A failing battery can cause corrosion through excessive off-gassing. The terminal looks so bad I doubt external cleaning will restore the connection. Finally, make sure the ground connection to the body next to the negative terminal is clean and tight. And BTW, no need to do anything fancy with the terminals. High quality ends of the style you have can be bought at any auto parts store.

 

[SWUtah]

Get a new Toyota battery.

 

[REZARF]

Get a new Toyota battery.

$900 bucks, not me

I am going to swap over to a AGM and put on some new OEM terminals... or go to a pure audio system style which I have enjoyed in the past on my 40. All other connections are clean.

 

[Sandroad]

The 27F Toyota TrueStart is only $109 at my dealer. AGM may be a good idea, but only after you're sure the system is not overcharging. AGM batteries don't like to be overcharged. AGM in the 27F size are few and far between and double (+) the cost of the Toyota battery.

 

[Output Shaft]

The corrosion is caused by overcharging the battery and poor venting of the battery while it's being overcharged.

The acid mist from off gassing cells is causing all of that mayhem.

Now that the plating of that cheap terminal has been corroded off by the acid, only raw steel remains, which corrodes just by looking at it.

Replace the battery. Replace the terminal. And check to make sure your charging voltage is not too high.