Rust in box new truck

Newbie so go easy.
I did some research (another tacoma world thread talked a bit about it) but I am wondering if anyone else is having this issue ? Truck has less then 300 miles on it, never had anything put in the box yet.
The other thread mentioned it was caused by rivnuts/ bolts for the rails but I've used stainless bolts that came with my tonneau cover, and when installing I didn't see any rust in the bolt holes (rivnuts). It is still happening and I'm worried it maybe something different then the rivnuts/bolts. I don't want to spray Fluid Film /Rust Check everywhere and just hope for the best on a brand new truck.
Should I go back to dealership or ... ?
Thanks for any help.

 

Plastic does not rust! Looks like some sort of dirt to me. Have you tried cleaning it up?

 

Damn

 

It looks like rust to me. The kind that is created with moisture and then is dripping/spraying onto the bed.

@tacoma2023 - keep looking until you find the raw steel that is rusting and dripping inside the bed. I bet your tonneau cover is leaking.

 

Cleaned it up and it came back. It is 100% rust, and I know the bed isn't rusting (composite) but I am wondering where it is coming from. First time I noticed, it was rusty brown water in the bed thats coming from somewhere else and this is what it looks like after drying.

 

I would go to dealer it’s a new truck!

 

Well then, it would have to be coming from somewhere above. That would pretty much limit it to your cover or bed rails I would think. Maybe pull the bed rail cap off and see if that is rusting underneath the plastic.

 

@JasonLee I looked for bare steel and couldn't see any when I took the rails and everything off, so I am worried something important is rusting somewhere I can't see.
And yes, tonneau cover might be leaking a bit but doesnt explain why water is rusty.

 

@Buck Henry I will have to take the rails/tonneau cover off and have another look.
This was an issue before I put the tonneau cover on tho.

 

I'll put a bet in.

The fasteners they used to move the bed rails down and attach the tonneau rails are not stainless and are rusting. As it rains/water drops, it pulls off some of it and then dries in the bed.

Replace one side with the same hardware but stainless, and see if it fixes it on that side.

(Assuming that all looks like aluminum hardware for the brackets and whatnot in there)

 

Do you park underneath an awning at work or somewheres?

 

Bring it to the dealer make sure it is documented.

looking at pics it’s coming from top of bed Tonneau or something wheel wells and bed sides also have it.

 

If this is the case, then maybe it is time to stop by the dealer and ask where the rust is coming from.

 

Probably famous railroad dust. Power wash

 

@tinker_troy Not parked under anything.

@GarlicDude I used all stainless bolts/washers when I installed the tonneau cover and moved the rails (threw out old bolts). Only thing not stainless is whatever is recieving the bolts (rivnuts probably) inside the bed.

I guess my biggest worry is that something besides those rivnuts is rusting.

@Jeffch @JasonLee going to go to dealership tomorrow.

 

Dont expect much from the dealer. It has to be something you added unless it was there when you picked up the truck. Take everything new off and ride for a while and see if it goes away. Narrow from there.

 

Do you live and/or work near a railroad track? Or do you work at a machine shop? Looks like rust from airborne particles to me.

 

Can’t make this shit up!
We have a train yard with round house a block away. Amtrak runs nightly.
I work at a machine shop 25yrs now.
Never had this!

 

You drilled holes in the track during the relocate, correct?

 

If any steel was drilled then it is probably the chips/shavings from the drilling. My rear bumper looked the same way after I installed bed stiffeners (and failed to clean up the drilling debris afterwards).