Remove the master cylinder.
Inspect and note these items:
Before reassembling, check that all parts are free of dirt and other foreign particles.
Do not try to disassemble the master cylinder assembly. Replace the master cylinder assembly with a new part, if necessary.
Do not allow dirt or foreign matter to contaminate the brake fluid.
Install the master cylinder.
Safe Driving
...
Reporting Safety Defects
In the U.S.
If you believe that your vehicle has a defect which could cause a crash or
could cause injury or death, you
should immediately inform the National Highway Traffic Safety Administration ...
A/T Housing Idler Gear Shaft Removal and Installation (A/T)
Remove the snap ring (A), the cotter retainer (B), and the cotters (C)
from the idler gear shaft (D), then remove the idler gear shaft. Do not
distort the snap ring.
Check ...