Owner noted unusual sound when applying brake pedal in a hard, but not panic, stop. Investigation revealed that the power brake booster was extending out 1 inch from firewall when hard brake pedal pressure was applied. Brakes functioned normally. Further investigation revealed that the four studs which secure the brake booster to the firewall were not tightened properly. The four nuts which secure the four booster studs to the firewall were only engaged the length of the nut, leaving about 1 inch of the stud thread exposed. Owner fastened three of the four nuts, since the fourth stud was obscured by the steering column. The fourth nut will be referred to the dealer for repair during the next scheduled maintenance. Brakes now function ok without noise or booster movement, but this failure to properly assemble the booster to the firewall could have caused loss of brakes if the four nuts had totally disengaged from the booster studs.

- Warren, MI, USA