Do you really want an amateur, such as yourself, working on something as vital as your Anti-Lock Brake System, (ABS)? Take it to a professional. On 4WD models the front ABS are not serviceable, because the front wheel indicator rings are integrated with the front wheel bearings. On 2WD models the front ABS sensor is mounted in the steering knuckle which are pressed onto the wheel hubs. The rear wheel sensor is mounted on the rear axle housing. This information is for later than 1994 models.