Prevents water and dust from getting inside of the steering rack or degrading the inner tie rod end If your BMW's steering rack boots are torn we suggest replacing them immediately. The reason for this is the boot serves an important functional purpose. The boot keeps dirt, moisture, and other foreign objects from degrading the steering rack seal or inner tie rod joint. FCP recommends replacing these steering rack boots when installing new inner tie rod ends or tie rod assemblies to ensure leak free operation.