01 XG300 rear right wheel randomly brakes by itself

[mystr]

hello, back in february i bought a 2001 XG300 and now i have this problem. sometimes, randomly, only the rear right wheel brakes by itself, it may be hard or more sudden but it happens and i don't know why. i thought it was a mechalical problem, i told it to my official hyundai mechanic and they greased the brake calipers, but the problem happened again. When it happens it's very uncomfortable, the car decelarates and the rear right wheel becomes very hot and smell of burning material can be noticed.

Recently i did put my battery in recharge and when i did put it back in the car the problem resurfaced. then i disconnected the negative pole for about 5 minutes to reset the ECU and after that the problem was gone, but it resurfaced more suddenly later in the day. Now i'm thinking of some electric/electronic problem, maybe hydraulic?

Now i often test the car smoothness by putting it to neutral and testing how it decelarates at low speeds, and if it goes naturally back and forward on slightly inclined roads. But even if the car seems to act 90% correctly i can tell that there's someting wrong when i feel that the rear right weel is warmer than the left one.

Can someone help?

[mystr]

when i said that the problem resurfaced later in the day i was intended more subtly, even today i tested it after a 30 mins trip and the rear right was warm while the left one was perfectly cold.
the 2 front ones where just a bit warm.
the car seems smooth but i could say not 100%

[sbr711]

See if the pads is stuck/seized in the mounting bracket...

You have the mount bracket, pads, and a shim at each end of the pad at the bracket.. remove the pads and shims from the bracket,, remove the rust from the brackets down to smooth clean metal where the shim actually fits, re-install the shims, knock the rust off the pads' ears, and see if the pads actually fit in the mounts without being stuck...

[mystr]

Thank You for your help. do you intend that the pads must be seized in the mounting brackets in order to work or the contrary? I don't understand the working principle.
i don't know if i can do it by myself, i'll tell it to the mechanic. i forgot to say that i recently had all four wheels pads replaced with new original ones by the hyundai mechanic, but the problem was there even before the pads replacement. last time i had this problem i did shut off the engine, waited minutes and restarted multiple times, pressed the brake pedal with variable force, tried to engage/disengage the parking brake with no results. then i disconnected the battery for 5 minutes and the problem was gone. how can this be possible? Previous times i had to stop the car for several hours in order for the problem to dissappear.

[mystr]

Ok, i've got it repaired, forver i hope.
however, now, the two front wheels develope a small heat, thing that i didn't notice before. My mechanic says that it's normal for wheels to develope heat because -he says- the pads must slightly touch the brake disc.

I thought pads should not touch the brake disc at all, if the brake pedal is not depressed. If they touch the disc, even slightly, doesn't this cause a small resistance to the car advancement?
What's correct and what's not?

Thanks

[mystr]

Problem solved by my own: i've found that if i activate the parking brake before turning off the engine and deactivate it only after the engine start, the wheels remain cold, no pad contact on the rotor. And my mpg are increasing!

I advise you to touch your wheels after a trip, if you feel warm there's something wrong, the brakes drag and you're probably consuming more fuel than necessary. My wheels now are cold and the brakes function perfectly!