fixing undercarriage rust (PICS)

[Steamfitter]

I have a 4 year old T4R ('13), with 103,000KM on it (64,000 miles). I bought it new, and payed for the diamond-kote rust proofing/undercoating and paint protection at the dealership, and additionally my Toyota ECP warranty has just expired (at 100,000 km).


I recently noticed rusting on the receiver hitch, and I got down under the vehicle and noticed rust in a number of spots. There is rust on the axles, and it's basically slowly hitting everything. I live in Northern Canada (it's winter 1/2 the year), and yes they salt the roads quite a bit. However, this vehicle has been well maintained and 90% highway driven so I am surprised to see this taking place, especially after I paid for the undercoating/rust treatments from the dealership.

How bad is this rusting? What should I do it fix this? I am going to contact toyota service and see what they say (they claim to be able to fix rust damage), however I am disappointed that after paying for rust-proofing that this is happening only 4 years later. I would like my t4r to last for 20 years.

I have asked about rusting here before, but that was before I realized I already had extensive rust damage.

 

[nb rob]

Hello,

This is surface rust. I work in structural steel, and all of the steel is kept outside. It is covered in a fine layer of surface rust. Step one is always media blasting the rust off of the steel, and it looks brand new, with negligible difference to the dimensions and structural properties of the steel.

That being said; Hit it with fluid film. It the same amount of time that it took you to write this post and take photos, you could have touched that all up with fluid film, and everything would be jet black underneath.

I live in eastern Canada, and we get horrendous salt too. A very small amount of continuous maintenance keeps my vehicles looking better than new cars on the local lots.

Canadian tire carries fluid film. Keep it away from plastics and rubbers.

For the trailer hitch, I would hit that with a wire brush and spray some rust paint on it.
I do that probably twice a year. It looks factory fresh.

Regards,

-Rob

 

[Steamfitter]

Hello,

This is surface rust. I work in structural steel, and all of the steel is kept outside. It is covered in a fine layer of surface rust. Step one is always media blasting the rust off of the steel, and it looks brand new, with negligible difference to the dimensions and structural properties of the steel.

That being said; Hit it with fluid film. It the same amount of time that it took you to write this post and take photos, you could have touched that all up with fluid film, and everything would be jet black underneath.

I live in eastern Canada, and we get horrendous salt too. A very small amount of continuous maintenance keeps my vehicles looking better than new cars on the local lots.

Canadian tire carries fluid film. Keep it away from plastics and rubbers.

For the trailer hitch, I would hit that with a wire brush and spray some rust paint on it.
I do that probably twice a year. It looks factory fresh.

Regards,

-Rob

So just spray fluid film directly onto the undercarriage rust and it will neutralize it ? That would be nice. Crawling under and trying to scrape and clean everything would be a real *****.

 

[ToyoT4R]

Fluid Film, looks like interesting stuff. I may pick some up and try it.

https://m.advanceautoparts.com/p/fl...mIKHZaRrXTBYllwyo0UNPxoCpRTw_wcB&gclsrc=aw.ds

 

[greatape]

Welcome to salt roads...only so much you can do as your vehicle will succumb to it eventually over time no matter what...

 

[nb rob]

So just spray fluid film directly onto the undercarriage rust and it will neutralize it ? That would be nice. Crawling under and trying to scrape and clean everything would be a real *****.

I wish I could show you some before and after....
Believe it or not, that is really not bad at all.

Hit the frame pieces and rocker panels. Rust prevention is an ongoing thing, but easy to do.

I used to do a yearly application of dripless amber oil (undercoating) , but the fluid film is inexpensive and very easy to apply.

It WILL distort plastics and make rubber door seals expand and sag though. Just be smart about the usage. I keep a cloth handy to wipe off wayward spray. I use a cardboard shield, as ghetto as that sounds. Makes everything very easy.

I also use boeshield on my suspension components, but that's another story.

I am militant on rust. It's easy to prevent and maintain a clean chassis.

 

[audiciter]

You live in Canada and didn't get Krown rust-proofing?

I had Krown applied (not at the dealership) the day I bought mine and had (and will have) it re-applied every spring. Mine has only seen two winters in Northern Ohio, but they do salt heavily here and mine still looks new underneath.

I was surprised to even find a Krown application business here, but luckily it was right down the road from me.

 

[bythehour]

The receiver on my 2015 4R looked like that; I was pretty disappointed. She was stolen over the winter and I replaced it with a GX of similar age/mileage - same thing. Lots of surface rust all over the underbody. Both have more rust than our 7 year old MB, which is a daily driver and parked outdoors....

 

[WreckTheShop]

For the trailer hitch, I would hit that with a wire brush and spray some rust paint on it.
I do that probably twice a year. It looks factory fresh.
b

Would it be worth it to do this all over the undercarriage and then later apply fluid film? If the rust has already advanced as far as OP's photos.

 

[nb rob]

Would it be worth it to do this all over the undercarriage and then later apply fluid film? If the rust has already advanced as far as OP's photos.

paint the undercarriage and then put fluid film on it?
seems unnecessary to me. I'm talking about less than a 3 minutes of touching up fluidfilm once or twice a year. If you're going to go through that trouble, you might as well go all out and apply POR15. There's a good thread on the tacomaworld forum where someone went all out with POR15.

If you want to paint the underside though, prep properly.

The reason I recommend paint for the trailer hitch is because you will definitely ruin some clothes brushing up against an oily trailer hitch receiver.

 

[Dalko43]

Fluid film offers a way to mitigate rust, not to completely remove it or stop it.

I apply fluid film 1x a year, usually before winter. I can't really tell if it's working or not, but a lot of people swear by it.

To truly clean off existing rust, you need to media blast or scrape off the existing rust spots, prime it and paint. It's a lengthy process, especially the prep work, but can dividends in the long run by allowing your vehicle to stay on the road longer.

 

[nb rob]

here's some sliders that some would consider badly rusted.
I took them off after 2 years and sandblasted them and repainted them.

This is a great example of surface rust.

 

[nb rob]

unpainted steel will rust. period.
But a coating of oil (fluidfilm) will definitely prevent moisture from contacting the bare steel.

a painted coating will be beat up from rock chips, etc. And those spots will rust. Immediately.

Is this rust a concern? Not if you keep on top of it.

 

[DavidR1]

When spraying the fluid film on the undercarriage do I need to be very careful not to get any on the rubber and plastic pieces under there?

 

[Runn4est]

When spraying the fluid film on the undercarriage do I need to be very careful not to get any on the rubber and plastic pieces under there?

I have not had any issues, but I don't just spray like crazy. I target as much metal as I can, if I get a little overspray on the rubber or plastics, it hasn't caused any issues. I do really steer clear of the exhaust though!

I haven't used the air gun though, just the spray cans. Maybe with the air gun it's harder to be so selective? Either way it states that it is safe on many plastics and rubbers.

 

[Steamfitter]

unpainted steel will rust. period.
But a coating of oil (fluidfilm) will definitely prevent moisture from contacting the bare steel.

a painted coating will be beat up from rock chips, etc. And those spots will rust. Immediately.

Is this rust a concern? Not if you keep on top of it.

What's better? Annual fluid film DIY, or annual krown under coating?

 

[Dawyd]

Either should be fine as long as it is reapplied annually before the next salt season.

I've had annual B&R rust check applied at the local business on my 95 truck since brand new and have not had any rust until the last 2 years when I neglected to have the undercoating done before the snow fell, now everything is crusted heavily underneath and the wheel wells have started to crumble away. Need to stay on top of it otherwise it spreads quickly.

I'm pretty sure B&R does a 2 step process, one fluid is deep penetrating (gets inside seams and behind hard to reach areas) and the second is the heavy greasy fluid that coats the underside.

Your rust looks very minor as well, I would continue the annual spraying to prevent further corrosion.

My old neighbor bought a new tacoma trd (~2007) and had to scrap it in 3 years because he wouldnt do any preventative maintenance against road salt. Body and frame crumbled to junk. Sad because it was such a nice looking vehicle.