Driveway Rust Stains from Chevy / GMC 2000

[Yorker]

Probably a dumb question but I haven't yet found the source of the rust stains on my driveway that appear to be coming from the front bumper area of my truck. Anyone else have this experience?

My one-owner 2000 GMC Sierra 5.3 4x4 ext cab long bed looks and still smells like new and only has 33K on it. It does sit out mostly uncovered but always clean and freshly waxed.

Recently I noticed a fair amount of rust staining going on my driveway under the front bumper area. I crawled under it and noticed that the backside of the bumper had surface rust on it so I steel wooled / rubbed it off as best I could where I could see and sprayed flat black rustoleum on the area. But I'm still getting it though not as bad.

It isn't radiator overflow and it doesn't seem to be battery related but it is coming from somewhere. I'm going to have to put it up on stands and remove some of the fender underpanels, etc to see what is going on. The source that I've seen most relevant is at the driver's side and center of the truck but under the area behind the bumper.

If I was 25 years younger I'd be more eager and adept at crawling around under it.

[silverhairdeere]

try looking under your battery box .

shd

[Crmzendrgone]

Could be that you have nothing but water in your cooling system and your seals on the rad. cap is bad so it leaks out of there and runs down. The nothing but water in the system will cause a rusty muddy looking fluid. Just a thought not saying thats what it is but I have seen that before.

I agree with battery too. Mine did that awhile ago would get hot and boil over. did exactly what you did wire wooled the area and painted it, oh and got a new battery.

[gmctrucks]

I say the radiator theory sounds good and so does the battery lift battery and look at the tray or maybe some joker placed a cigarette in that area and it's wet and dripping tobacco it can happen. I'm being silly if not im going to go crazy in my house.
Please help! GMC

[leolkfrm]

have the whole underside rust proofed, and see if it goes away

[Yorker]

Thanks for the replies and suggestions. I've pulled the battery, cleaned and repainted the tray, checked the antifreeze and examined the front bumper underside from left to right and still can't see a specific source. I've repainted certain areas that showed any surface rust. I'll see what happens now.

That might be a good idea to get the undercarriage re-sprayed / rust proofed. This staining is something that just started this year and I thought it might be something that other owners of this model have run into.

[silverhairdeere]

just a thought , i've seen some driveways that had rust stains in them from the hind of gravel that was ued in them . only in one spot .

shd