Power steering fluid is not present on most current Lexus RX 350 models because the steering system is electric. If you own an older hydraulic-model RX 350, the reservoir is located in the engine bay on the passenger side near the firewall.
This article explains both scenarios, how to identify which system your RX 350 uses, and where to look if you do need to service hydraulic power steering on older models.
Electric power steering: no reservoir
In newer RX 350 models (roughly from the mid-2010s onward), Lexus uses electric power steering (EPS). The EPS system uses an electric motor and electronic control rather than a hydraulic pump and fluid reservoir. There is no power steering fluid to check or fill, and any steering problems are addressed as an electrical/assist system issue rather than a fluid issue.
How to confirm your model’s steering type
Look for signs of EPS rather than a hydraulic pump and fluid reservoir. If your vehicle lacks a power steering fluid cap and there are no hydraulic hoses feeding a pump, it’s most likely EPS. You can also verify by checking the owner's manual or contacting a Lexus dealer with your VIN, which will specify whether the vehicle uses EPS or a hydraulic setup.
Hydraulic power steering (older RX 350): where to find the reservoir
For older RX 350s that still use hydraulic power steering, the reservoir is located in the engine bay on the passenger side, typically near the firewall. It is a small plastic bottle with a cap labeled “Power Steering Fluid” or “PSF,” and the reservoir is usually translucent so you can see the fluid level.
Before you start, ensure the engine is off and cool. If you need to service the fluid, follow the steps below.
To locate and check the fluid on hydraulic systems, follow these steps:
- Open the hood and look on the passenger side of the engine bay near the firewall for a small plastic reservoir with a cap labeled Power Steering Fluid or PSF.
- Check the fluid level against the monitors or markings on the reservoir (MIN/MAX). If it’s below the minimum, you’ll need to add fluid.
- Fluid type: Use Toyota Power Steering Fluid or ATF Dexron II/III (as specified in your owner's manual). Do not mix with other fluids unless the manual permits it.
- Filling: Remove the cap, use a clean funnel, and add fluid slowly until it reaches the MAX line. Replace the cap securely.
- Bleeding air: With the engine running, turn the steering wheel from lock to lock several times to help bleed air from the system. Check for leaks and recheck the fluid level if needed.
- Leaks and wear: Inspect hoses, clamps, and the reservoir for cracks or leaks. If you notice persistent leaks or a whine/low-assist condition, have the system inspected by a professional.
Location can vary slightly by year and trim, so always consult the owner's manual or a service manual for your RX 350’s exact year and VIN for precise instructions.
Summary
Most modern Lexus RX 350 models use electric power steering, which means there is no power steering fluid reservoir to check or fill. If you own an older hydraulic-power-steering RX 350, the reservoir is typically located in the engine bay on the passenger side near the firewall, and you should follow the manual’s guidance on fluid type, level, and bleeding procedures. When in doubt, contact a Lexus service professional to confirm the system type and the correct maintenance steps for your specific vehicle.