Twice in the past two months, the power steering in my 1999 Toyota Camry has temporarily stopped working. The first time, I was making a turn out of a parking lot, and the wheel froze up (or at least became very difficult to turn). The problem completely disappeared after about 30 seconds. Two months later, the problem happened again while making a turn onto a busy street. This time, it lasted only about 10 seconds before recovering. Both times, the wheel seemed to lock after I had already turned it some amount - i.e., halfway through the turn. And both times, it was raining. I did not hear any unusual noises - e.g., belts slipping.
I have taken the car to two different mechanics (one of them the local Toyota dealer), and neither could find anything wrong with the power steering. From their visual inspection, the power steering fluid looks good, there are no obvious leaks in the system, and the power steering belt looks fine. And they were unable to replicate the problem, since it occurs so infrequently.
The mechanics have said that there are two most likely culprits - a faulty rack and pinion ($1800), or a bad power steering pump ($800). I am hesitant to spend this kind of money without believing that the problem would be fixed, but I’m also very uncomfortable driving the car when the steering could give out at any time.
Any suggestions on what the problem might be, or how I should proceed? The car has about 100,000 miles on it and is otherwise in great shape, so I’d like to keep driving it for years to come…