Small Brake Fluid Leak for Toyota

This bulletin concerns some 2011-2015 Toyota Prius and 2012-2015 Prius Plug-in Hybrid vehicles.
Some 2011-2015 Toyota Prius and 2012-2015 Prius Plug-in Hybrid vehicles may exhibit a condition where the brake, anti-lock brake system (ABS) and/or active traction control (TRAC) warning lights are on and/or a check vehicle stability control (VSC) message displays. Diagnostic trouble codes (DTCs) C1391, C1252 and C1253 may be stored. This condition may be caused by a small internal brake fluid leak inside the brake booster assembly with the master cylinder.
Are the brake, ABS and/or TRAC warning lights on and/or does a check VSC message appear on the display? If yes, continue to Step 2.
Using Techstream, check and record any DTCs. If the afore-mentioned codes are set, continue to Step 3.
Remove the brake booster assembly with the master cylinder.
Remove the brake booster pump assembly.
Install a new brake booster assembly with the master cylinder.
Install a new brake booster pump assembly.
Test drive to confirm the repair.