Brake lightswill not work aven after changing Bulbs. What could be the problem?

Have you checked the fuse under the bonnet? 15 Amp fuse marked in red on the photo below.

Do turn signals work ok? Do you have current at the brake switch?

When you say you checked the fuse, are you getting power in and out of it and the brake light switch ?

Usually a problem with the turn signal switch.

If both are not working that is a sign that you have some other problem and not burned out filament's in the bulbs bulbs. Try turning on the four way flashers and then off again a few times do the rear lights flash? if so the bulbs are ok. If the brake light still don't work check the bulb socket with a DC volt meter while the rake lights are help on by a helper, if you have voltage then likely the bulbs are the problem. If you still think the bulbs are the problem the way to change them is outlined in the owners manual with diagram's which I do not have.

Assuming the bulbs are good, replace Relay #46 located in the underhood fuse panel.

Does the brake light in the rear window work? If so, the brake light switch is good. Running lights all work?

Have you checked the fuse for the brake lights and have you checked the brake light switch.
The brake light switch is directly above your foot when it is placed on the brake pedal.

make sure u have put the right bulbs in. rear brake lamps are dual filament....

do you have a 3rd brake light like on that is on the roof or in the rear window? if so does it work?
the brake lights are usually a 2way bulb so just because the lights work doesn't mean that brake lights will. if the 3rd brake light works replace the brake light bulbs if none of them work including your 3 brake light. check into having your brake switch changed. that is the switch under the brake pedal. when it is pressed the brake lights come on and when released they go off. if the bulbs do not fix the problem than try the switch.