I'm puzzled

[gophergunner]

Ok, on my 2006 sierra something is leaking. Its on the passengers side, it leaks onto the tire and gets thrown around as I drive and gets lots of other stuff wet.

Right now I'm a bit puzzled because I can't find anything actually leaking, but I honestly think its coming from the battery.

I did the old fashioned "taste test" of the mystery fluid and as soon as it touches my tongue it burns.....coolant doesn't burn like this. But yet the battery is dry when the truck is sitting. I also noticed that some of the metal parts that are getting wet sure look clean. Rust is removed from steel in a few spots.

So this leads me to believe right now that when I drive for a while the battery is possibly overcharging and boiling over and leaking all around. I have just noticed today and haven't taken the truck for along enough drive to get the battery cookin that well.

Just curious if I'm on the right track with the battery here or if I should be looking to something else?

Any input is welcome and appreciated. Thanks in advance.

[DmaxMaverick]

If it is the battery, get it addressed quick! Is the battery tray getting wet? It will strip the paint and start to corrode very quickly if it's battery acid. BTW....the "taste test" is a real bad idea when it comes to sulfuric acid. It can permanently damage flesh, including your tongue. It doesn't take much, or very long.

If it isn't the battery, it's probably condensation from the A/C. Could be from the evaporator drain (just behind the tire), the accumulator (vertical aluminum canister at the firewall), or bare plumbing. Look for "sweat" on the components while the A/C is on. This is more pronounced at higher humidity levels.

[gophergunner]

There is some sweat on the a/c lines but it just tastes like water. The stuff thats bothering me really does burn the tongue when I tried the taste test.

I did remove the battery and everything was dry around it, including the tray and that blanket that goes around the battery. This is why I'm puzzled by it, I figured the battery tray would at least have some evidence of a leak somewhere.

[DmaxMaverick]

The taste may be misleading. It depends on where you are sampling it. Right off the lines, it should be pure condensate water, and have no taste (other than a slight "aluminum" or metallic taste). If you sampled moisture that's wicked down through a bunch of other stuff, it would pick up that taste, including past acidic residues, salt, dirt, or other stuff I wouldn't put on my tongue.

Brush on some baking soda and water mix. If it bubbles up, you have acid, and should be able to trace it to the source. Baking soda is totally inert, and won't damage anything, but should neutralize any acid present.

[madmatt]

you got two batteries,, switch sides and see if the leak moves.

[gophergunner]

Well I just might have to try these tricks now. If it is the battery I'd like to find out sooner rather than later so it doesn't wreck some stuff for me.

I'm probably going to switch the batteries around too. And lets just say the leak follows the battery....then is it just a bad battery? And would replacing it be a solution or could it be something else causing the battery to leak when its charging?

Thanks for the input!!!

[DmaxMaverick]

The batteries are hard-wired parallel, with no isolation like on gassers with an aux. battery. If you have an overcharging issue, it should effect both batteries. If only one battery is leaking, it is a battery problem. This is assuming the rest of your electrical system is healthy (it should be, the truck is still new). The possibility exists one battery has a poor terminal connection, causing a bias. But, voltage regulation (PCM controlled) should not allow an overcharge, under any condition. A more likely candidate (if the "leak" remains at the location) would involve excessive vibration or heat exposure. (all the more reason to use Optima batteries)

[Mark Rinker]

There is a vent - easily located - on top edge of OEM AC/Delco batteries. You could try slipping plastic tubing over that vent and routing it into a clear plastic jar. See if you catch anything.

I have experienced the passenger side battery venting a small amount of acid - usually while towing in the hottest summer time on most my Duramax trucks, some worse than others. (My '05 LLY was the worst, I suspect its underhood temps were highest...)

[gophergunner]

Since I removed and reinstalled the battery the leak has gone away. I'm left with some very rusty spots on my frame but no matter how much I drive recently, the leak hasn't come back.

I think some Optimas might be in the works before the cold weather hits.:cool: