Brake Drum

Reference: Rear Brake Drum Removal and Installation 

Inspect brake drum for wear.

If drum inner diameter is exceeds the limit or uneven or stepped wear is excessive, replace the drum.

Drum inner diameter "a" 

Standard: 220 mm (8.66 in.) 

Limit: 222 mm (8.74 in.) 

Fig 1: Measuring Drum Inner Diameter

Courtesy of SUZUKI OF AMERICA CORP.