Whatever model Jeep you drive, the brakes all work the same way in terms of energy. It requires less energy to stop the rear wheels from rotating than it does the front wheels. If the same amount of braking power were applied to the rear and front wheels, the rear wheels might lock up. So when you're doing a brake job on your own Jeep, a brake proportioning valve is an essential part. 4WD carries replacement brake proportioning valves from Jeep® plus aftermarket valves from top manufacturers like Stainless Steel Brakes and Inline.