How hot can your brake rotor be after drive?

[wolf4runner]

after about 30 mins of city driving (stop and go), I found that my rotors ( especially front) were extremely hot. Pour some water and it dryout very fast.

The wheels are just warm tho.

Should I suspect a seized caliper?

 

[mole177]

no...

lots of heat will be made to stop a 6000lb rig...

it's normal.

 

[Casper421]

no...

lots of heat will be made to stop a 6000lb rig...

it's normal.

Last time I checked we don't have 3 ton rigs. On second thought, Thejosh might.

 

[M1911]

Rotors are supposed to get very hot.

 

[Mike07SE]

You're totally fine. Even a couple of minutes of driving will have them hot, let a alone 30 minutes of stop and go. Rotors will get hot no matter what after a drive. Spritz some water on them and they boil off instantly.

When they smell like they're burning is when you have a problem.

 

[BlackWorksInc]

You're totally fine. Even a couple of minutes of driving will have them hot, let a alone 30 minutes of stop and go. Rotors will get hot no matter what after a drive. Spritz some water on them and they boil off instantly.

When they smell like they're burning is when you have a problem.

Yeah, well almost every itty bitty sedan, domestic truck, and similar vehicles I test drive up and down a hill near our dealership (fair steep, curvy, great for loading up a car on a test drive) burns the brakes by the time I get to the bottom of the hill, they're usually smoking and I heavily engine brake (to test the trans and load the engine up.)

That being said, your brakes will easily surpass 400*F (I don't remember what the actual temp is, but I know they get hotter than that) under normal sustained braking. I would refrain from quenching the brakes when their hot, cast iron isn't too happy when you do that. Unless your brakes are excessively smoking/burning and or you are experiencing brake fade I would not worry about how hot the brakes get.

 

[Tresvn]

I have been using one of those point and shoot thermometers to check my brakes over the past 2 weeks, I just replaced the pads and front rotors and want to make sure i dont need calipers too. I know, its backwards. I have been getting readings of about 210*-250*, this is just driving around the city here, rarely over 40mph on drives of 30 mins or more.

Back brakes are usually a little warmer 250ish , fronts are 210- 220ish, my passenger side is usually a little cooler too I assume this is due to me and the gas tank adding more weight to the drivers side.

 

[BlackWorksInc]

I have been using one of those point and shoot thermometers to check my brakes over the past 2 weeks, I just replaced the pads and front rotors and want to make sure i dont need calipers too. I know, its backwards. I have been getting readings of about 210*-250*, this is just driving around the city here, rarely over 40mph on drives of 30 mins or more.

Back brakes are usually a little warmer 250ish , fronts are 210- 220ish, my passenger side is usually a little cooler too I assume this is due to me and the gas tank adding more weight to the drivers side.

That sounds about right, you have to remember that when you brake all that momentum and force is transfered to the front of the vehicle. This is why the rear brakes are often smaller as they don't normally handle as much weight when braking. I also could be off on my temperature, I could have sworn it was higher than 400*F but looking at some stuff in Google (haven't read any of the NTHSA or DOT studies) seems like that is average temp for normal driving.

 

[riceandpho]

i would avoid putting water on hot brakes, u can warp the rotors.

 

[emoore924]

I race cars and without cooling on the track the front rotors can get over 800. Easily. They literally start to glow red.

On the street, I've checked them (looking for a frozen caliper) and the fronts of my t4r run about 150-200. The rears slightly less. That's with essentially "normal" street driving. Not towing. Not driving hard. I think most of my cars run in that range on the street. I did catch a frozen caliper on another car and it was running off the scale (888+)

If you're running >300 on the street and you're driving "normally", I'd be looking for a dragging caliper.

 

[46runner]

Rotor Temps

I've been reading about the stuck caliper issues on this forum. I decided to use a laser temp gauge to measure the temp of my rotors. After driving about 30 minutes in 30 degree F temp. Here are my average temps per tire from taking the temp from several spots on each rotor.
Front Left: 80-100F
Front Right: 80-100F
Rear Left: 300-350F
Rear Right: 100-115F

Curious to hear what you'd do next. And don't recommend moving to a warmer climate

 

[MikeInNH]

Here are my average temps per tire from taking the temp from several spots on each rotor.
Front Left: 80-100F
Front Right: 80-100F
Rear Left: 300-350F
Rear Right: 100-115F

Looks like the left-rear caliper is sticking.

 

[Dylan]

I had a frozen rear caliper that I replaced this summer...in addition to the front two having at least one piston frozen. It happens.

 

[46runner]

I had a frozen rear caliper that I replaced this summer...in addition to the front two having at least one piston frozen. It happens.

Dylan, did you have to replace rotor and pads too? I was planning to just swap out the caliper. I also don't know how long its been like this. When I rotated my tires 2 months ago, the pads looked good all around.

 

[46runner]

rear brake job

I planned to just replace the rear left caliper but ended up doing rotor/caliper/pads on both rears. Napa parts. Rotor temps: Rears: ~85F, Fronts: 95-105F. Feeling good.