Jeep: Shaking steering wheel when braking, jeep grand cherokee, composite rotors

Question
Hello!...Recently on my 1998 Jeep Grand Cherokee I put 4 new tires.The tire store did a wheel alignment. Since then I have noticed that when braking from the higher speeds, such as highway speeds ...the steering wheel shakes and you can feel a pulse type vibration through the brake pedal. This has gotten worse in the past week and I am taking it to a Jeep dealer on Tuesday. I would like to have an idea of what might be wrong before I go there. I am thinking it may be a brake issue or front end aligmnent problem, yet around town it is fine. Please tell me what you think. I so appreciate any help you can offer this lady!

Answer
For starters, I never and I mean never, take my Jeeps back to the dealer once the warranty has expired. They use factory priced parts and charge the highest shop rates around (usually). A common problem on a Grand Cherokee - front brake rotors are warped.  Jeep used composite rotors and they tend to warp easily.  Take your Jeep to a brake shop (not the dealer) and have them turn (reface) the rotors, if they cannot be turned, have them install a new set of "cast iron" aftermarket brake rotors.  This should eliminate the frequent need to have front rotors turned.