One problem related to brake disc rotor has been reported for the 1998 Toyota Toyota Truck. The most recently reported issues are listed below.
My Toyota 4 runner has 100000 miles and I am having my rotors turned for the third time. They warp after about 5000 miles and then I just put up with it for another 25 or 30 thousand miles until I can't stand the bumping any longer and have them turned again. It appears that they are not substantial enough for the weight of the vehicle or the abs system may be causing some sort of pulsed drag that causes uneven drag and warpage.