While operating the vehicle a loud "bang" was heard from the rear of the vehicle causing a momentary moving disturbance (shimmy). Upon stopping the vehicle to inspect, I noticed there was no longer any tension on the parking brake. Continuing to drive indicated that the brake was seized on one wheel and loose/rattling parts from somewhere near the rear wheel. Further investigation has so far revealed that this may not be an uncommon problem for S60 Volvo with repeated complaints appearing on enthusiasts sites including incidents of both rear wheels seizing while the vehicle is in operation. Consultation with the two nearest Volvo dealerships indicates no acknowledgment from Volvo of the defect. It appears the problem may be with the internal parts associated with the return mechanisms in the parking brake assembly. As this is potentially a serious safety item I believe it would be beneficial to have the NHTSA review this problem as many S60 Volvo will have reached similar service lives.

- Portsmouth, NH, USA