Replacing Brake Fluid
Changing your own brake fluid isn't for everyone, but it can certainly be done with the right know-how.
If you're the “do-it-yourself" type and have both the patience and the location to do the work, our guide can help you replace your brake fluid and even decide if your vehicle needs to see a mechanic.
Why Clean Brake Fluid Matters
The good news is brake fluid doesn't get dirty like oil, nor evaporate like coolant. But, depending on your climate, brake fluid can absorb moisture, which ends up lowering the boiling temperature. When this happens, the effectiveness of the fluid is reduced—and it could even damage your braking system.
When to Change Brake Fluid
There are a few ways you can determine if it's time to change your brake fluid.
- Consult the vehicle owner's manual.
- The manufacturer may recommend changing brake fluid when your vehicle reaches a certain number of years or miles, which should be listed in your handbook.
- Ask a trusted mechanic.
- Mechanics have the expertise to diagnose your vehicle's issues quickly and efficiently. That being said, make sure you consult a mechanic you trust, as others may suggest a timeframe that is much sooner than necessary just to get your business.
- Do a visual exam.
- Brake fluid is typically clear or translucent, not dirty or rust-colored.
- Conduct a brake test.
- If your brakes feel mushy or require a lot of pressure to engage, your brake fluid may need to be flushed or changed.
Precautions to Take
No matter what make or model your vehicle, there are a few things to keep in mind before attempting to change your brake fluid.
- Only use recommended brake fluid. The wrong fluid could damage your vehicle's brake system. Consult your owner's manual for guidance.
- Do not use brake fluid if the container seal is broken. Dirt, water or other contaminants can result in brake system damage or failure.
- Wear gloves and protective eyewear. Brake fluid is toxic and should not touch your skin or eyes.
Acceptable fluid level is between the minimum and maximum line. Replace brake fluid if it is below the minimum line to prevent brake system damage.
Before you start, make sure you have the following items handy:
For changing your fluid:
- New, unopened container of brake fluid.
- Turkey baster (for removing brake fluid).
- Clean rags.
For bleeding your brake lines:
- Clear container (plastic or glass).
- Vinyl tubing.
- Lug wrench.
- Vehicle jack and jack stand.
Steps to Changing Brake Fluid
Here are the basic steps to follow in order to change your vehicle's brake fluid.
- Park your vehicle on a flat, level area. Be sure to set the parking brake.
- Prop open the hood and locate the master cylinder reservoir. Consult the owner's manual if necessary.
- Using the clean rag, wipe off the outside of the master cylinder cap. This step prevents dirt or dust from getting inside.
- Using the turkey baster, suck the brake fluid out of the master cylinder reservoir.
- If possible, wipe the interior of the master cylinder with another clean rag.
- Pour new brake fluid into the reservoir. Make sure it does not go above the “Full" or “Maximum" line.
- Replace the reservoir cap.
Bleeding the Brakes
Removing and replacing brake fluid is just one part of the process. You'll also need to bleed the brakes in order to remove extra air out of the brake lines.
For this step you'll need a partner, so ask a friend or family member to help. Once the new brake fluid is in place, follow these steps:
- Using a lug wrench, loosen all wheel lug nuts—but do not remove them entirely.
- Place a jack in the correct spot under your vehicle and jack it up until the wheel is off the ground. Consult your owner's manual for the proper placement.
- Use the jack stand to secure your elevated vehicle.
- Repeat Step 3 to lift all wheels off the ground.
- Now is time to remove the lug nuts and wheels completely. Safely set all parts aside to make sure you don't lose any.
- Starting with the rear passenger side brake, locate the brake bleeder valve. Your owner's manual can help you identify the bleeder valve.
- Connect one end of the vinyl tubing to the valve, and place the other inside the clear plastic bottle.
- Ask your helper to gently push the brake pedal down a few times, and then hold it all the way down.
- Slowly open the bleeder valve. The old brake fluid along with any air bubbles will be pushed out and into the clear container.
- With pressure still applied, tighten the bleeder valve.
- Ask your helper to release the brake pedal.
- Repeat Steps 8-11 until no more air bubbles flow out with the clean brake fluid.
- Tighten the bleeder valve.
Repeat the entire process on all remaining wheels (Steps 6-13). Do not forget to check the master cylinder level after bleeding the last brake.
Once you've finished, reinstall the wheels and tighten the lug nuts before lowering the vehicle back to the ground. Give the lug nuts one more twist once your vehicle is on the ground to make sure they are nice and tight.
While your car is safely parked, give the brakes a push to make sure they feel solid before taking your vehicle for a careful test drive.
Remember, this is not an easy do-it-yourself project. If any of these steps seems too daunting, you don't have the proper equipment or you can't get someone to help, don't risk damaging your brake system. There's no shame in taking your vehicle to a mechanic you trust for this type of job.
For more information, we've put together a comprehensive guide on general vehicle maintenance and safety that can help you out. Happy driving!