The official notice
Defect
Certain vehicles use brake fluids containing polymers that act as lubricants for certain brake system components. If during vehicle maintenance, brake fluid is used that does not contain such polymers or only small amounts, part of the internal rubber seal located at the end of the brake master cylinder piston may become dry and may curl during movement of the piston. If this occurs, a small amount of the brake fluid could slowly leak from the brake master cylinder into the brake booster, resulting in illumination of the brake warning lamp. If the brake warning light has illuminated and the vehicle continues to be operated without refilling the master cylinder brake fluid reservoir, the driver will begin to notice a spongy or soft brake pedal feel and braking performance may gradually decline. This will increase the stopping distance, increasing the likelihood of a crash.
Safety Risk
No risk description available.
Remedy
Dealers will replace the brake master cylinder seal with a newly designed one.