[Hoss911sc]

I suggest starting simple and checking that both bulbs are making contact for the tail light and brake light function. Easy to do. If the bulbs are at all loose it can cause the issue you are describing. The contacts in the socket can be less than tight due to a weak design(IMHO). I had the same issue and assumed the switch on the master cylinder was the issue but checked the bulbs first and they were moving in the poorly designed socket. If the bulbs and contacts are fine, then the switch would be the next potential culprit. I had to use a fix I found here on the board of adding solder to the 2 bulb contacts and then filing back for a tight, solid fit. Fixed my problem. Good Luck