My front brakes have been getting very hot. So hot that you can feel the heat radiating while standing next to them, and they smell.

This is my 3rd 4Runner. I have towed trailers with them, mild off roading, driven all over Alaska and a significant portion of the lower 48 with them, and NEVER smelled hot brakes. The strange thing is the two most notable times I have smelled hot brakes have been on pretty minor drives, one of which was going entirely uphill!

Its a 2021 TRD ORP with 7800 miles. Since purchasing it I have installed a transmission cooler, put airbags in the back, 1 Inch spacers in the back, and Bilstein 5100s up front set to 1.75. I have done all mods and maintenance myself. The brake reservoir has not been opened since I purchased the vehicle.

Today I took off the front wheels, calipers, and rotors for inspection. Absolutely nothing out of the ordinary to mention, other than the fact that the front right rotor required the old screw-through method to dislodge it from the hub. Surprised it was stuck considering low miles on a truck that has only been between Texas, Utah, Nevada, and California with no towing or anyting crazy. The heat must have fused it on there.

I did a tiny bleed of the brakes for fun. The fluid smells strange vs any brake fluid I've smelled before. It smells like DOT4 mixed with full power Windex - if that makes any sense.

I'm stumped and can't find any stories of other 5th gens with this issue, and Id rather not run to the dealer over this. It's also strange cause it's not every time I drive, regardless of distance. You guys have any idea what it could be? What am I missing? Did lifting the vehicle put extra pressure on the system somehow? Seems impossible to me. Did the manufacturer put some weird crap in the fluid? Any input is appreciated.

I doubt that your lift and other mods did anything to affect the brakes. Since it is still under warranty, I would have the dealer look at it.

Since it is affecting both sides, it could be the master cylinder is sticking or something in the ABS system.

Do you use both feet when driving, i.e. left foot on the brake and right foot on the accelerator pedal? If so, you could be riding the brakes which will make them overheat.

i had some corrosion in my front brakes early on. but we get salt and snow over here. My fronts were getting sticky at less then 5000 miles i believe. I went with a bbk, and never looked back. The brakes are known issues for people that see a lot of salted roads.

If you touch the front wheels after driving, is there a perceived temperature difference between the left and right front? It's unlikely that both calipers are sticking (but I guess not impossible) and you should feel a difference in heat. I had a seized caliper on a different car once and also smelled brakes. The temp difference between the wheels was easily detectable.

Any rotor discoloration at all? Bluish or dark kind of tint? Perhaps pull the pads and see if they are wearing evenly between inner and outer. That might tell you if there's an issue as well.

Nope, I do not use both feet while driving. Again I have put many thousands of miles on various 5th gen 4Runners without ever having this issue.

Absolutely no salt encountered, but I did get into a little bit of red sand in Utah.

As I mentioned I pulled everything apart yesterday and inspected very thoroughly. Absolutely no unusual wear, no discoloration, nothing interesting or noteworthy at all.

And yeah, the really strange thing here is that both fronts are get equally hot! I haven't noticed anything from the rears, but honestly they do such a minimal amount of the work that maybe they just aren't heating up as much.....

I guess I should look into if the master cylinder is causing the issue I'll leave that to the dealership though.

Have you noticed dips in gas mileage? If there are severe brake issues then you might notice increased fuel consumption.

Calipers piston stuck, rust. If notice early no need to replace burned fluid.

You might also check the service history of the dealership that sold it new, just in case the previous owner had it serviced for a similar problem.

My 2021 ORP was like that also, front brakes smelled very hot and also dusting tremendously. After 700 miles I changed the front pads to NAPA adaptive one pads and smell and dust is gone, I'll probably change the rear pads to those also even though the rear pads never have smelled hot or dusted too much.

I second this comment!

I actually have used Fuelly since the very first tank of gas and there is no drop in mileage whatsoever.

I bought it brand new. No service record to speak of.

Both front calipers stuck simultaneously?

I was in San Antonio during the ice storm this last winter where they used very mild amounts of saline solution on the roads but there is nothing more than light surface rust down there.