Brake light light is on on the dash board - but brake light bulb works

Check the brake fluid level if it is low the red brake warning will illuminate. If the fluid level is low there may be a leak or the brake ads may just be worn. A defective emergency brake light switch could also cause the light to come on. If the timing belt needs to be replaced replacing the water pump as part of that job would be labor efficient as it would be a duplication of labor to replace the water pump at a later time.