The 1991 4Runner uses a hydraulic power steering system with a dedicated fluid called ATF (Automatic Transmission Fluid).
Here's why:
* Compatibility: The seals and components in the power steering system are designed to work with ATF. Using traditional power steering fluid can cause damage.
* Performance: ATF provides better lubrication and performance for the power steering system.
* Manufacturer Recommendations: Toyota specifically recommends ATF for this model year.
Here's what you need to do:
1. Check your owner's manual: It will explicitly state what type of fluid to use.
2. Use Toyota ATF: You can use Toyota's genuine ATF fluid, or a compatible ATF fluid from another reputable brand (like Valvoline, Mobil, etc.).
3. Avoid mixing fluids: Do not mix different types of power steering fluids.
Remember, it's crucial to use the correct fluid to ensure the longevity and proper functioning of your power steering system.
