Whenever I stear or press the breaks on my truck, it makes a whining noise and there is vibration. I checked my fluid level and the fluid was foamy. I have also noticed I have a slow leak in the fluid. Would the whining noise be due to air getting in the system, and is there an easy way to fix this? Any help would be appriciated. Also, I am stationed in Portsmouth, NH, are there any good local shops in the area?