Hey guys i just had my rear brake pads replaced and was curious if anyone has heard of this on their car? I hadn't, and i google'd it and didn't really come up with anything? The 'mechanic' explained it as a spot that gets very hot on the rotor and has made the metal very hard?

I figured it was a plot to get more money out of me... so i declined and just got done what i had asked for.

1 more question: How bad is it, on a scale from 1-10 is it to have cracked ball bearing joints? or CV joints, i can't remember the name? Thanks

 

hot spots are from the rotors being warped.

 

on a scale from 1-10 it's 11 or 12. could not even resurface them.

 

does not seem to be the right answer.

 

hot spots are when certain spots on your rotor/drum change metal composition. it is usually caused by overheating/stressing and then they cool down too quickly. the hotspots themsleves will have lower coefficient of friction and you can try to resurface them but usually it will be through the whole rotor/drum.

usually people would say you have a cracked axle boot or cv joint boot. if the boot is cracked, it realy dpeneds on how long its been like that for. if its recent and everything is still wet, their is probably minimal contamination. it would be best to change it asap. if its already dried out, your bearings are probably scratched up and damaged. either get a remanufactured axle, oem axle replacement, or replace the boot and leave it (not the proper way) either way youd rather have it fixed as it will cause vibrations and noises

 

ok you are right on that because warped rotors and hot spots are two different thing now that i think about it.

 

concur....if this is on the rears, most likely you were driving alot and heated up the brakes and then you parked and yanked up the ebrake. When the ebrake was pulled tight on the hot rotors, it created this "hard spot" on your rotor. It's well known in autocrossing that after each run, you NEVER put the ebrake on...just park the car and leave it in gear.

It also could happen if you were braking hard alot and then stopped at a light and were holding the brake pedal down.

In any case, rear rotors are pretty cheap to replace so I would look into it (I suggest Importrp for good prices).

yup, he is correct here too....call Raxles and get a new axle if that is the case. You should be able to look down there and see if your CV boot is torn.

Now, if he said you have a cracked lower balljoint you need to replace that IMMEDIATELY, because if it breaks, the car will go out of control and you will wreck.

You need to clarify with the mechanic what exactly the problem is, and listen more carefully next time to what he's talking about.

Also, go buy a Haynes manual at your local auto parts store so you know what you're talking about in terms of parts....

 

A "hard spot" can also occur in the casting process, I've come across this while machining cast iron several times, the "hard spot" can not be machined away. And when it is present in a rotor, you will always experence a plusing in the brake pedal during braking [the higher the speed the faster the pluse], it will most likey get worse, you will not be happy with this condition, a rotor replacement is the only solution

 

To the both of you guys, Thanks! This was very helpful and IIRC he said its torn and "grease is flying out of there" or something to that extent. When i get some free time i'll look into the situation a bit more.

 

if thats the case then its your axle boot. change the boot asap before your cvjoint gets **** in there