We recently took our 1999 Jeep Grand Cherokee, Limited into our local repair mechanic for replacement of the power brake booster because we were advised that it was in need of replacemnt because a loud squealing sound is emitted when first stepping on the brakes. They said it was due to a vacuum leak in the booster.
The brakes involuntarily locked-up after driving 2 miles on high traffic surface streets while driving our car home from the mechanic’s place of business. He says that the new booster he purchased by vin number from Jeep is the cause of our problem because it is faulty. 1.)Is it possible to get a faulty new brake booster from a Jeep dealership when it is ordered by the vehicle vin number? 2.)Is it possible that our mechanic installed the booster incorrecly (he had to fiddle with the brake lights which would not go out when releasing foot pressure on the pedal as we arrived to pick-up or vehicle)? 3.)Are there any peculiar cautions that our mechanic should have observed when installing a replacement power brake booster on our 1999 Jeep Grand Cherokee, Limited vehicle?
It is possible that the new brake booster was bad and it is also possible that it was installed incorrectly. The fact that the brake pedal had to be adjusted to turn out the brake lights indicate that the push rod was too short to match the pedal or that the brake boost was self applying itself because of a sticking or leaking apply valve.
If everything is okay now, I would not worry.
It is possible to get a faulty booster, yes. Let the mechanic install another one and see if that solves the problem.