Buying used car disc brakes

I’m interested in buying a friend’s disc brakes.
They are obviously used and this guy drives quite aggressively and his car is tuned and he drifts and stuff and speeds a lot which means lots of braking as well.
What concerns me is, does the whole mechanism degrade in any way if you use it aggressively like he does? Or is it 100% fine if I simply replace some parts of it, like the brake pads?
Point is: Is it worth buying it from him?
Let me know, thanks.
Answer #1
You should buy new Rotors and Calipers, brakes are very important.
Answer #2
If the brakes are still installed on the car then jack each wheel up and check for runout. If the discs are perfectly aligned, have no or very little wear, and the pistons have no leaks or damage to the boots then there’s no problem. If there’s a small lip on the disc from wear but they are straight then measure the thickness to make sure they’re still in spec. Also check the slides work perfectly and don’t stick anywhere in their bores. I’m a mechanic with 9 years experience so I have some idea.
Answer #3
Thanks spudster for your technical instructions!
However, what I’m asking is more general.
What parts of a disc brake system can be worn out from the aggressive use of this guy? (e.g. calipers, rotors, brake pads etc). Are there parts that will definitely need replacement to be on the safe side?
I also posted this question on yahoo answers you can see some of the feedback I got there too.
http://answers.yahoo.com/question/index?qid=20120206052205AA4A4SS
Answer #4
Souns like a bad idea to buy used brakes for a car. Those parts wear out and should only be replaced by new ones. At least then you know they are safe. Not worth to risk it with something this important.
Answer #5
blindscout replied: Thanks spudster for your technical instructions!
However, what I'm asking is more general.
What parts of a disc brake system can be worn out from the aggressive use of this guy? (e.g. calipers, rotors, brake pads etc). Are there parts that will definitely need replacement to be on the safe side?
I also posted this question on yahoo answers you can see some of the feedback I got there too.
http://answers.yahoo.com/question/index?qid=20120206052205AA4A4SS
If the discs are not blue from overheating and the rest of my advice is followed then they’ll be fine. Definately put in new pads. If the discs have any glazing on them then get Bendix pads with the titanium strips on them which will clean it off. Disc brakes are generally tough enough to handle a fair bit of abuse.