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Owning a Toyota Prius comes with the advantage of low maintenance, but certain essential tasks, like checking and changing the transmission fluid, should not be overlooked. 

In this comprehensive guide, we’ll explore the significance of Prius transmission fluid, when to check it, how to determine if it needs changing, and step-by-step instructions for a fluid change.

The Importance of Prius Transmission Fluid

The transmission fluid in your Prius plays a crucial role in maintaining the overall health of your vehicle. Regularly replacing this fluid is as vital as routine oil changes, contributing to the longevity and efficiency of your hybrid car.

Checking Prius Transmission Fluid

While many vehicles have a dipstick for fluid checks, Prius models come with sealed transmissions, making manual checks more challenging. However, a check valve under the transmission allows you to assess the fluid color. 

A bright red-pink hue indicates good condition, while a dark red-brown suggests the need for a change. Ensure the vehicle is level when checking, preferably on a hydraulic lift handled by a professional mechanic.

When to Change Transmission Fluid

Despite claims of a “lifetime” fluid by Toyota, it’s advisable to check Prius transmission fluid every 30,000 miles and consider changing it at 60,000 and 90,000-mile intervals. Regular assessments are crucial for optimal performance.

Signs Your Prius Transmission Fluid Needs Changing

Apart from mileage considerations, the “maintenance required” light on your dashboard serves as an indicator for low transmission fluid levels. 

Unusual behavior in your hybrid, such as high RPM at low speeds, struggles uphill, elevated transmission temperature, or an unresponsive vehicle, may also signal the need for a fluid change.

DIY Prius Transmission Fluid Change

While professional mechanics may charge upwards of $300 for a transmission fluid change, you can perform this task yourself with the following supplies:

• Ramps, jack, or lift
• Torque wrench
• Socket wrench
• 24mm socket head
• 10mm hex socket
• Drain pan
• 1 or 5-gallon bucket
• Funnel with extension hose
• Toyota ATF WS transmission fluid (4 quarts)
• 2 gasket washers (crush washers)
• Dropcloth or newspaper
• Oil pan

Step-by-Step Fluid Change Process

1. Lift the Car: Use ramps, a jack, or a lift to elevate the car for easy access. Ensure the vehicle is level and use a drop or newspapers to absorb potential spills.
2. Remove Plugs: Locate and remove the drain plug and fill plug. The 24mm socket head removes the fill plug, while the 10mm hex socket removes the drain plug. Place a bucket underneath to catch draining fluid.
3. Drain the Fluid: Allow the fluid to drain, and pop the hood for better access. Clean and replace the crush washers on both plugs while waiting for drainage completion.
4. Replace Drain Plug: Once drained, use the torque wrench and 10mm hex socket to secure the drain plug at 29 ft-lb.
5. Add Fluid: Thread an extension hose through the hood, attach a funnel, and refill with approximately four quarts of Toyota ATF WS transmission fluid. Stop when the fluid reaches the top of the fill plug.
6. Replace Fill Plug: Secure the fill plug with a torque wrench and 24mm socket head at 29 ft-lb.

Alternative Tools for Fluid Change

Consider using a vacuum transfer pump, an electric pump, or a hand pump for a more convenient fluid change process.

In conclusion, while changing Prius transmission fluid might seem daunting, following these steps ensures a smooth process. Remember that proper maintenance, including regular fluid checks and battery health assessments, contributes significantly to the overall performance and durability of your Prius. 

If hybrid battery replacement becomes necessary, explore top-notch new and reconditioned options for enhanced longevity and performance.