Brake rear drums overheating My LC 80 series '90 GX model has been having reoccurring left side rear overheating after driving for 2-3 hours in traffic. It has been worked on many times since the last attempt both sides heated to about 100-110F on the rim with the right one the hotter. The wheel cylinders have been replaced, the brake shoes, bearings and seals on the left side in the hub with the springs, self adjuster and cable in the drum, the front disc pads also. There has been some engineering: welding on the lh rear axle diff tube which was done. The problem stressed out the last mechanic any help is needed. He wants to replace the master cylinder next. Stumped on what to do next ?