99 brake light failure

Two times in the past six months both oif my side brake lights have failed to work, the top third light works ok. When the brake lights failed I also found out that the 4 way flasher would not work. I worked the flasher switch a number of times and the flasher relay started to work. I then found out the brake lights again worked. The last time they failed I again checked and the flasher relay would not work. Operated the flasher switch a few times it started to work and restored the brake lights also.

I did not think the flashers effected the brakelights, but rather the turn signals. Has anyone else experienced this type of problem and if so what did you do to correct it?

Thanks