A. Inspect Master Cylinder Date Code

1. The date code is the TOP code located on the front (forward) boss of the aluminum master cylinder, and consists of 4 numbers and a letter (the letter is not important for this service). The first number indicates the calendar year built and the next three numbers indicate the day of the year. Any master cylinders with a date code of 3309 or earlier must be replaced (Figure 1).

2. If the master cylinder date code is 3310 or later, no further action is required. If the date code is 3309 or earlier, replace the master cylinder as instructed in Section B.