Can you do a Transmission Flush on CVT Transmission?

When it comes to vehicle maintenance, one of the most debated topics among car enthusiasts and mechanics alike is whether you should perform a transmission flush on a Continuously Variable Transmission (CVT). Traditional automatic transmissions and manual transmissions are well-understood, but CVTs have their own unique characteristics, making the question more complex.

In this guide, we’ll explore the specifics of CVTs, whether it’s safe to perform a transmission flush on them, and what alternatives exist to maintain a healthy transmission.

The Purpose of a Transmission Flush

A transmission flush involves draining all the old transmission fluid from your vehicle and replacing it with fresh fluid. It is done to:

• Remove dirt, debris, and old fluid that may be contaminating the transmission.
• Improve transmission performance by restoring the fluid’s ability to lubricate, cool, and clean.
• Help prolong the life of the transmission by keeping the fluid clean and maintaining optimal functionality.

Read this full guide about Transmission Flush.

Can You Perform a Transmission Flush on a CVT?

Short Answer: It depends.

CVTs have unique requirements compared to traditional automatic transmissions, and this includes their fluid. The use of a transmission flush on a CVT is generally a more delicate procedure. Here’s why:

1. CVT Fluid Specificity

CVT fluid is specially formulated to work with the pulleys and belts in a CVT. Unlike regular transmission fluid, CVT fluid has different friction properties, which are crucial for the operation of the transmission. Using the wrong fluid or flushing the system too aggressively can damage the transmission components.

In some cases, manufacturers may not recommend a full flush, especially for newer CVT systems, as it could lead to a loss of lubrication or a change in the fluid’s properties, which can negatively affect the CVT’s performance.

2. Risk of Overflushing

In a traditional transmission flush, the system is flushed with a machine that pushes the old fluid out and replaces it with fresh fluid. With a CVT, this process can be risky because overflushing may cause overpressure that could damage the seals and other internal components of the transmission.

CVTs have very specific fluid levels, and if the system is not flushed carefully, the risk of introducing air into the transmission is higher, which can cause erratic shifting or even transmission failure.

3. Manufacturer Recommendations

Some vehicle manufacturers explicitly advise against performing a full transmission flush on a CVT. Instead, they may recommend drain-and-fill procedures, where only a portion of the fluid is drained and replaced. This helps maintain fluid levels without disrupting the internal balance of the transmission system.

Always refer to your vehicle’s owner’s manual or consult with the manufacturer to check if a flush is recommended or if an alternative method is preferred.

Alternatives to a Full Transmission Flush on a CVT

If you’re concerned about your CVT fluid and want to maintain its performance, here are some alternatives to a full transmission flush:

1. Drain and Fill

Drain and fill is the most commonly recommended procedure for CVTs. This method involves draining the old fluid and replacing it with fresh fluid, but it does not involve the aggressive flushing process.

This method is safer because it avoids the risks of overflushing or damaging the transmission seals. While it doesn’t remove all of the old fluid, it’s still effective in maintaining the transmission’s health.

This procedure may need to be repeated multiple times to fully replace the old fluid over several intervals.

2. Fluid Replacement at Regular Intervals

• Regular fluid replacement is the best practice for CVT maintenance. Most CVTs have a recommended fluid change interval (usually around 30,000 to 60,000 miles). By changing the fluid at regular intervals, you help ensure the transmission stays clean and operates smoothly.
• Some manufacturers may offer a special type of fluid that is designed to be long-life and requires fewer changes.

3. Using Transmission Fluid Additives

• There are some transmission fluid additives available that claim to improve the condition of your CVT fluid. These additives may help clean the internal components and restore the fluid’s performance. However, it’s essential to verify with the manufacturer if such additives are safe for your specific CVT model.

Signs Your CVT May Need Fluid Maintenance

It’s important to keep an eye out for any warning signs that your CVT may need fluid maintenance. Some common symptoms include:

• Slipping gears or hesitation when accelerating.
• Grinding or whining noises from the transmission.
• Delayed or erratic shifting.
• Warning lights on the dashboard (such as the transmission or check engine light).
• Poor acceleration or stalling at higher speeds.

Conclusion

In summary, while it is technically possible to perform a transmission flush on a CVT, it is not always recommended due to the potential risks involved. Many manufacturers advise against flushing CVTs, as it could lead to damage. Instead, drain-and-fill procedures, along with regular fluid replacements, are typically the safer and more effective options for maintaining a CVT’s health.

If you are unsure about the maintenance requirements for your CVT, it’s always best to consult with a professional mechanic or refer to your vehicle’s owner’s manual for the recommended transmission fluid service intervals and procedures.

By following the right maintenance practices, you can ensure that your CVT continues to deliver smooth and efficient performance for years to come.