Power steering fluid doesn't typically need to be replaced all that often. Low levels of power steering fluid could be indicative of a leak or a problem with the power steering pump. Older cars may naturally lose some power steering fluid over time, in which case fixing the issue is simply a matter of buying some more fluid and topping off the reservoir levels. If you've had a sudden decrease in power steering, you've probably got a more complex problem than a slow leak. This is something that Stop Leak will not fix, so don't bother. If you can have a friend turn the steering wheel with the engine on while you observe the power steering fluid levels, you may be able to narrow down the problem.
There are generally 4 points of failure for a power steering leak.
- The pump
- The high pressure hose
- The return hose
- The steering rack