Very hot lug nuts after short drive?

This doesn't sound good. I suspect the brake fluid has been contaminated with a petroleum product. Another possible cause is if someone changed the length of the power booster's push rod, or on some models, the brake light switch is misadjusted and is holding the brake pedal partially applied.

First, stop on a slight incline, shift to neutral, release the brakes and see if the vehicle creeps downhill on its own. If it doesn't, first pull the brake pedal up with your toes. Next, place a block downhill of one tire, about a foot away, then loosen the steel lines attached to the master cylinder. If that lets trapped brake fluid release, that proves everything below that point is okay. Look at the rubber bladder seal under the reservoir cap to see if it is ballooned up and mushy, or feels slimy. That's what happens to rubber parts when they're contaminated with engine oil, power steering fluid, transmission fluid, penetrating oil, or axle grease.

Let me know what you find up to this point. I'll be back around this time tomorrow to figure out where to go next.

Your car has 4 wheel abs with EBD it stands for electronic brake force distribution also if its the se model it also has brake assist and electronic stability control.I think the problem may be in the ebd unit its basically like a electronic brake distribution block of a sorts it works with all 4 wheels might be sticking .I'd have it checked soon it might need re calibration watch for the abs light on the dash or a check engine light it might have brake fault codes. Good luck

I believe there was a recall on the electronic braking system in 2020 for the Elantra it talked about moisture problems in the electronic control unit or something maybe call the nearest Hyundai dealer and see if there's a braking recall to see ft yours is covered they'l most likely need your vin number and can probably tell you right over the phone and if it is on the recall list theyl probably fix it for free. Until then drive safely best of luck

Be sure to check out the recall info down below. I'm not sure if its still active but it think there's a case number and it says Wich cars are included. Anyway be well

Thanks for that information. Too bad they didn't spell out any other symptoms that could occur. It seems like too often, "increased risk of fire" is a catch-all to cover themselves of any liability issues.

The wrong length push rod in the power booster is the least likely cause of dragging brakes unless that was just worked on, but we don't want to overlook it. Same with the brake light switch. I'm very relieved the rubber seal in the reservoir cap is okay.

A common cause of just one dragging brake is a constricted rubber flex hose at one wheel. Often there's a metal bracket crimped around the middle of the hose, and rust builds up inside that crimp until it squeezes the hose closed. You can force brake fluid through it to apply the brake, but that trapped fluid can't return to release it. The clue here is it only affects one wheel. To identify that, again, stop on a slight incline, place a block a little downhill of one tire, then you have to crawl underneath and open the bleeder screw on that caliper.

When this happens to all four wheels, we have to look for what they have in common. Normally that's the master cylinder. When the brake fluid becomes contaminated with a petroleum product, the rubber parts swell and become mushy or slimy. In the master cylinder, the rubber lip seals grow past the fluid return ports, blocking them. That keeps the brakes applied lightly, but since the fluid can't return to the reservoir, it warms up from the hot brake pads, then expands to apply the brake even harder. When this type of failure occurs, you can release that pressurized fluid by loosening the steel lines at the master cylinder.

I hope Mechtrix has the right solution. The only proper fix for contaminated fluid is very expensive. That is to remove every part that has a rubber part that contact's brake fluid, flush and dry the steel lines, then install all new rubber parts. That can include calipers, wheel cylinders, flex hoses, master cylinder and cover, combination valve, rear height-sensing proportioning valve, (when used), and the hydraulic controller, (when used). If any part is not replaced, the contamination can leach out of it and recontaminate the new fluid and new parts. The repair cost can exceed the value of older cars.

To illustrate how serious this can be, back in the mid 1980s, it was common to use a "bleeder ball" to pressurize brake hydraulic systems to aid in bleeding them after other routine services. Those balls held close to five gallons of new brake fluid. To fill them from such a big can, it was customary to use a long funnel. At a Sears Auto Center out west, the mechanic knew about this contamination problem, so when he grabbed the funnel they normally used for engine oil, he conscientiously wiped it out first with a shop rag, then used it to fill the bleeder ball.

The result of that disaster was the film of oil residue still in the funnel contaminated the entire contents of the bleeder ball, and that contaminated brake fluid went into over a dozen cars. That cost the company a lot of money for repairs.

Years later, drawing on that story, I used to start out my "Brakes" classes by pouring fresh, clean brake fluid into two beakers, then I'd drop in a rubber lip seal from a wheel cylinder repair kit into each one. Last, I added one drop of engine oil or power steering fluid to one of them, then set them aside for one week. At the end of that week, the seal in the contaminated fluid had grown about 20 percent and was soft and mushy.

I've been involved with three cars with contaminated brake fluid. In every case it took a lot more than a week to show up. One was on an Edsel I bought on an auction. It drove fine for the first two or three months, then, on its last trip, I barely got 75 miles on a tank of gas. On my granite driveway, the right front tire was locked and skidded. That car had four drum brakes which require a lot more contamination to lock up compared to disc brakes.

Again, given the condition of the rubber seal under the reservoir cap, I'm much less likely to suspect contaminated brake fluid. Another thing to consider is rusted mounting surfaces that impede a caliper from moving freely to self-adjust, but that generally affects just one wheel or sometimes both front ones. Sticking parking brake cables can cause the rear wheels to become hot, but not the front.

I'll be waiting to hear what you do find so we can solve this.