Power steering is now universal on almost all cars and is undoubtedly better than the old mechanical systems in every way…except one. If the power system fails, does the steering still work? Can the car be safely driven? Bindy
Yes, but with greater difficulty…and therefore more slowly and more carefully.
All the mechanisms that link the steering wheel ring with the front wheels are still there. In modern systems they are power “assisted”, but they are not power “dependent”. Steering is too safety-critical for that to be allowed. The same applies to servo-assisted brakes!
However, if the power fails for whatever reason, the steering does not just become “unassisted “– it also becomes “resisted” by the hydraulic fluid that was used to provide the power. So, it does not just revert to the normal characteristics of manual steering; it becomes especially heavy.
If you practised with steering that weight and got used to it, then you could drive quite normally and safely. But because you are now accustomed to the very responsive and light feel of a power-assisted steering, the sudden lack of power and additional resistance is a very different proposition, demanding a quite different mind-set.
Manoeuvring the vehicle will need considerably more physical effort and demand more mental concentration to adjust to the slower response to turning the steering wheel, and the stronger tendency of the system to try to “unturn” itself (road wheels rotating at speed are being urged by centrifugal force to go straight). Unpowered steering needs more effort to turn, and (you need to remind yourself) more effort to keep it turned.
To understand that principle, imagine what would happen if, in the middle of a corner, you let go of the steering wheel. What would the car do? Try it (for a microsecond!) at a moderate speed in a safe place to find out what “unturn” means and how quickly it happens.
