my new brakelight bulb holders don't work any better than the old ones. First bump in the road and the brake lights stop working. Any ideas on how to stop this. Bulb holder twists in ok but defective light signal comes on after a bump.

 

1. Have you twisted in the bulbs correctly into the holder. You can test the bulbs without putting them into the housing. You mention twisting in the holder but what about the bulb into the holder?
2. Are you using the correct bulbs with the side pins that lock when they are twisted into the holder?

 

yes, using correct bulbs and twisting both holder and bulb in correctly. I wedged a piece of wood in behind and that worked for a while until bump in road.