Turn Signal Flasher Unit problems of the 1996 Chevrolet Lumina

Failure of mfs causes brake lights not to work unless pull back on turn signal switch. This is the 2nd Lumina the company has owned that I have had this problem. Other car was 1992 same model & type. Dealer says they replace a lot of them. No indication is obvious that your brake lights are not working!! rather costly repair charge $300. 00 range as I recall from the 1992. Strange it happened on 1996 model also. Is there a secret recall or factory repair at no charge??.