Brake linings contain metallic particles to help dissipate heat. That metal is rusting to the brake drums. If this occurs after driving through puddles, there could be a rubber plug missing from the inspection holes in the backing plates. If it rains while the car sits undriven for many days, the humidity could cause the rust. More commonly, that will cause the wheel to lock up easily when you apply the brakes for the first time of the day, but they will release without problem.
A less common cause of easy lockup is weak shoe return springs. Most do-it-yourselfers just replace shoes when performing a brake job, but professionals usually will replace the springs and other hardware too.
Locking up solidly suggests one of the shoes is too close to the drum. The most common cause is a sticking parking brake cable that doesn't fully release. Next time this happens, try flexing the cable / casing assembly just in front of the wheel. If the brake releases, the cable should be replaced.
Tuesday, February 9th, 2010 AT 12:36 AM