How Often Do I Need to Change My Brake Fluid?


How Often Do I Need to Change My Brake Fluid?



Replace brake fluid

CARS.COM — The recommended intervals for changing brake fluid are all over the board depending on the manufacturer, from as often as every two years to actually never. Wait, never? Really, never.

Related: Can Brake Fluid Go Bad?

For example, Chevrolet calls for a brake fluid change on most models every 45,000 miles, but Honda says to do it every three years regardless of the vehicle's mileage. Three years is also the recommended interval for most Volkswagens, but Mercedes-Benz vehicles typically call for fresh fluid every two years or 20,000 miles. In contrast, on the Ford Escape, Hyundai Elantra, Toyota Camry and other models from those manufacturers, there are no recommendations for replacing the brake fluid, only instructions to inspect it periodically.

This leaves it up to the owner to consult what the manufacturer says in their car's maintenance schedule and rely on the advice of a trusted repair shop.

Brake fluid lives in a sealed system and can survive for years, but moisture from the surrounding air can work its way in through hoses and other parts of the brake system. If your brake fluid has become dirty or contaminated, it can change how your brake system operates — brake pedal feel can be affected, as can heat dissipation in repeated stops. Water in the brake lines lowers the boiling point of the fluid, so stopping ability can diminish in hard stops as heat in the system increases. In addition, over time the moisture can cause internal corrosion in the brake lines, calipers, the master cylinder and other components. 

Flushing and replacing brake fluid might cost $100 or less on many vehicles, but replacing rusted brake lines, brake calipers and other brake parts can run several hundreds of dollars, so clearly there's value in keeping up with maintenance. As a rule of thumb, it's wise to have the brake fluid inspected and tested for moisture content every few years, and no more than every five if you live in a high-humidity area. Drivers living in areas that get winter weather should also inspect their brake system frequently, as salt and other contaminants can get into the brake fluid. 

You might be able to tell it's time for a change by looking to see if the fluid is still fresh in the brake fluid reservoir, usually sitting on top of the master cylinder under the hood of your vehicle. Brake fluid is often light brown in color, and in some vehicles it's clear (at least when new) but will darken with age, becoming murky from water contamination. A better way is to have it tested by a professional for moisture and see what they recommend. Oftentimes you can have this service performed at the same place that performs a rapid oil change. Since the technician is already poking around under the hood, it's easy for them to take a sample and inspect all of your vehicle's fluids. 

Brake fluid is as vital to stopping a vehicle as engine oil is to keeping it going, but it doesn't get as much attention as it deserves.

Cars.com's Editorial department is your source for automotive news and reviews. In line with Cars.com's long-standing ethics policy, editors and reviewers don't accept gifts or free trips from automakers. The Editorial department is independent of Cars.com's advertising, sales and sponsored content departments.



Contributor Rick Popely has covered the auto industry for decades and hosts a weekly online radio show on TalkZone.com. Email Rick

When Should I Change my Oil?

An engine oil change is a relatively simple service. It’s widely touted as the single most important part of your car’s maintenance schedule.

There is a good reason for this. Nothing will shorten engine life faster than missed oil changes.

But how can you tell when you should change your oil?  

Advances in technology and increased consumer awareness have created some confusion to how often this needs to happen.

Visit our Car Maintenance Forum and discuss with others

The Easy Answer

For most of us, all we need to do is follow the manufacturer’s recommended maintenance schedule for oil change intervals. Their guidelines are designed to keep your car in good running condition for a long time.

Where can you find your car’s service schedule for oil changes and other recommended maintenance?

You can check the owner’s manual that hopefully you have kept in a handy place like your car’s glove box. You might also visit the manufacturer’s website and do a search to download it.

Quick lube shops have their own recommendations. One thing to remember is that these shops are speaking to a wide audience, addressing cars of every age, every mileage, and some with different needs.

While there is no harm done by too frequent oil changes, if your car doesn’t need them, that money could be better spent on other maintenance needs.

Don’t Put It Off

Service shops can change your oil fast. Image by By David Defoe.Service shops can change your oil fast. Image by By David Defoe.

If you have ever put off a trip to the grocery store or waited a couple of weeks longer between haircuts, don’t do that with oil changes.

Your oil’s primary function is to cut friction.

Over time, oil accumulates contaminants and loses viscosity (the ability to flow into every nook and cranny). Contaminants cause friction as parts rub together. Friction wears out those parts faster.

The damage caused by these conditions is largely irreversible without an engine overhaul or replacement.

Waiting for the low oil light to come on can be the worst thing you can do to your engine.

You shouldn’t see that light unless your oil level is low. So you don’t want to see it. Whatever amount of oil you do have left almost certainly has lost its ability to function properly.

The good news is that your service schedule is written to have this service done long before disaster is on the horizon.

Cars are Smarter Now

For a very long time the gold standard for oil changes was 3,000 to 3,500 miles.

There are still many adherents to this philosophy, but it may not be necessary;

Advances in engineering to both engine mechanical parts and especially to oil itself have extended the oil life cycle by more than double the old number.

Synthetic motor oil is recommended for some models. Image by Chris YarzabSynthetic motor oil is recommended for some models. Image by Chris Yarzab

Do you use synthetic oil? 

Automakers recommend it for some models. It cost a little more than regular oil, but it has had the biggest impact on oil life.

The life cycle for synthetics is typically 7,000 to 10,000 miles, a big change from conventional oil.

The type of driving we do also affects our oil change needs;

Frequent cold starts, extreme heat, and towing, are all examples of types of driving that can shorten our oil life.

Also, repeated short trips (under 4 miles) is one of the most overlooked enemies of oil life.

Any of these driving conditions can create the need to shorten your service interval by 25-40% depending on the severity.

oil change indicator percentageOil change indicator in a Honda Civic.

If your car is equipped with a maintenance reminder on the dash, some of the guesswork is eliminated for you.

Can you trust it?

For the most part, yes.

In the early days of automobiles the only way we had to track our vehicle’s aging was the odometer. But miles traveled is not always a good indicator of actual use for many urban environments.

[READ: Odometer Rollback Fraud – How to Protect Yourself]

With the inclusion of computers in the modern automobile we now have a way for the car to track time AND mileage. Time is important to this discussion because running time affects oil life.

But not all maintenance indicators work the same way:

Some use an electronic sensor to measure the oil quality, while others use an algorithm based on driving metrics to determine life expectancy.

If your car is not equipped with maintenance light or gauge, the owner’s manual should still be your guide.

Don’t Buy Cheap Oil

All of these scenarios assume you are using the factory-recommended lubricant.

If you have opted for something inferior you may be adversely affecting the recommendation.

It’s not worth a few dollars to shortcut on the oil.

Track Your Maintenance

Because time is important as well as mileage, it’s nice to try and plan your service visits.

The little sticker in the corner of the windshield was a small, important innovation to help us plan. Before that, many people kept a paper record in their glove box as well.

But now, with many of us carrying smart phones and having home computers, it’s gotten even easier..

Car Maintenance App

MyCarfax is a website – and a free smart phone app – that will track all of your car’s maintenance needs, making it even easier to keep track of, and plan, your next service.

Text Us!