ORIGINAL: Mspeed
If you are melting the disc in 5 mins then you have a serious problem. That fast you should be able to find the problem pretty quickly.
Agreed with mspeed ... The fuel line is to improve braking... Yours are rubbing - Ever ride a bicycle and the brakes are rubbing? Or leave a parking brake on in an automible and drive with it, or been with someone who has.... If the wheels spin freely without the brakes applied there is no way they can melt. Apply the brakes numerous times and spin the wheels to make sure they release. As for tuning read the manual or print it from the traxxas website. Tune to performance not temp.