Parking brake engages without warning while vehicle is underway. While the vehicle is underway at 30mph in a straight line, with no warning, one or both of the parking (emergency) brakes may engage, locking the rear wheel(s), and causing the car to slow abruptly or skid. The car has to be driven with the emergency brakes engaged to a safe place out of traffic. Once stopped, the condition can be cleared by depressing and holding the parking brake latch button and vigorously pumping the handle up and down. Once this has happened, the parking brake (a function performed by the emergency brakes) no longer engages consistently. Several mechanical disassemblies and inspections have not uncovered the cause, nor fully fixed the emergency brakes. A single, C-shaped, one-piece brake shoe that contacts a drum built within the rear brake rotor performs the emergency brake function on each rear wheel. An expander sits between the ends of the C and presses the ends of the brake shoe outward when the emergency brake lever is pulled. The design of this expander looks possibly faulty; little more than friction apparently holds it in position with the ends of the brake shoe. If it were to lose contact, or fall out of position, it might cause the emergency brake to engage unexpectedly. The photos are ones of the brake shoes and rotors discussed, recently replaced (again) in hopes of solving this problem.

- San Francisco, CA, USA