Q: How often is it necessary to change power steering fluid?

Unless there is a maintenance specification in the Factory Service Manual for your specific vehicle, it is not "required" to change the power steering fluid. However, it is wise to change the fluid at a reasonable interval because power steering fluid does accumulate wear products (bits of rubber, dirt, and abrasives) from throughout the system and these wear products will adversely affect the system seals, possibly shortening the service life of the pump and the rack assembly. A good rule of thumb is once you start to see significant discoloration of the fluid that is a good time to change it. The discoloration, of course, is your tip off that the fluid has become saturated with wear products. Apart from a visual check, you can assume that around 30,000 to 50,000 miles is not unreasonable as a service interval. If you are looking for something more definite, such doesn’t exist because estimates of service life for steering fluid, as published in the literature, range from 24,000 miles on up to 150,000 miles or more. The prudent course is to assume that significant fluid discoloration represents the point at which the fluid is holding a lot of contaminants and that can be your decision rule insofar as scheduling changes, or every 30,000 to 50,000 miles. If you desire this service it can be requested from YourMechanic as power steering fluid service. Let us know if you have further concerns.