Brake system repair under warrantee

[trobin]

At 9900 miles my 2012 Sonic had signs of a weak master brake cylinder - under steady foot force, the pedal would slowly sink to ward the floor. The (selling) Dealer agreed that the master brake cylinder was going bad, and replaced it under the 3 yr / 36K miles. I have not read of this being a common problem, hopefully. A paid rental car was provided.

 

[$ub$onic]

I think this might be the first I have Heard if this in a sonic. At least to what I have seen

 

[franl24fan]

brake master cylinder

I posted my experience under the brake system forum. Odd, but my sonic has the same mileage as yours and today the brake pedal went to the floor. Able to carefully drive it to the dealer this afternoon, they are ordering parts, got me into a rental car loaner , brand new fire engine red Impala, may not want my Sonic back. Obviously a recall needs to be issued, this could have been very dangerous.