The BMW power steering line and hoses are one of the luxury items that are not thought about until there is a failure in this system. Presently there are no current BMW cars that have the old style manual steering systems. If your power steering hose has a leak, the effort necessary for you to turn the steering wheel will be more than the old manual steering was. The purpose of the power steering lines and other parts are to supply all of the force required for the action of turning the wheels and to permit the input from the drive to only be applied with the use of a finger if desired. In contrast to the old style where both hands were required to apply the force needed to turn the wheel. The failure of a power steering line or hose can be determined when an oil spot is noticed on the ground where your BMW has been parked. This oil is noticeably different than engine oil because it will be cleaner. This is because there is no internal source of contamination like there is in an engine. To locate a leak, the engine must be running with one person moving the steering wheel while an observer looking at the power steering pressure line and return hose under the hood of your BMW. Because of the high pressure of this hydraulic fluid, the leak will appear as a squirt from the hose or line. If a leak is found then a replacement BMW power steering line and hose must be used, there is no patching that can be done to this component. The hydraulic fluid in the power steering system should also be replaced to remove any contamination that might have entered the system from the leak.