So, you’re finally replacing your brakes; you may think your work is done. However, you still have to complete the vital step of breaking in, – or bedding – your new brakes. Whether you replaced your brake pads, rotors, or both, breaking in your brakes extends their lifespan and improves their performance. This process can be broken down into a few simple steps.
How to break in new brakes:
- Start driving, and speed up to 60 mph
- Brake quickly to slow down to 20 mph
- Immediately speed back up to 60 mph
- Repeat step one 8-10 times
- Cruise at a high speed without braking for 5-10 minutes
Although this process sounds easy, there are many things to keep in mind to ensure you break in your brakes properly and safely. Below, we explain how brakes work, why the break-in or bed-in procedure is necessary and break down each step into further detail.
How Brakes Work
Before you start even planning to break in your brakes, you should understand how they work.
- Rotors spin along with your wheels as you drive.
- When you press the brake pedal, pressurized fluid travels through tubes from the reservoir toward your wheels.
- The fluid reaches your brake pads – there is one pad on either side of the rotor.
- The pressure of the fluid forces the pads towards each other, squeezing the rotor in between and forcing it to slow down to a stop.
There are many components of your car that contribute to proper braking, including:
- Brake fluid
- Fluid reservoir and transport tubes
- Brake pads
Each of these components are important to maintain. Keeping your brake full reservoir full and transport tubes clean ensure that there is enough pressure to squeeze together your brake pads when you hit the pedal, and your brake pads and rotors should be regularly replaced or serviced.
The break-in procedure for new brakes focuses on your brake pads and rotors. Your brake fluid, reservoir, and transport tubes are maintained through different methods, but are just as important to stay on top of. Talk to your mechanic to make sure your brake fluid reservoir is properly filled, and transport tubes regularly flushed.
Why Break in Brakes?
Breaking in your brakes is important, because your brake pads leave behind a layer of material, the transfer layer, on the rotors due to the friction when braking. The initial break-in process establishes an even deposition of the transfer layer on the rotors, by letting the brakes cool down while the car, and the rotors, are still in motion. By establishing this even transfer layer on the rotors, you are also ensuring that the brake pads don’t wear unevenly.
What Happens If You Don’t Break in Your Brakes?
If your brake pads are worn down unevenly, thus depositing the transfer layer unevenly, you will notice your car vibrating and shaking when you brake. This is due to the brake pads developing high and low spots where they have been worn more in certain spots than others. The high and low spots will become more and more exaggerated over time, causing the vibrating to worsen until you either have your rotors resurfaced, or you replace your brakes altogether. If you don’t break in your brakes, you’ll notice yourself needing to replace the pads and rotors more often.
Do You Need to Break in Your Brakes?
The short answer is yes. However, if you’ve paid a mechanic to replace your brake pads or rotors, they may have already performed this process before handing you back your keys. You should ask your mechanic if they’ve done this, to avoid putting unnecessary strain on your brakes by doing these steps a second time. If your mechanic has not done this process, or you’ve changed your brakes yourself, continue reading to ensure that you properly and safely complete the break-in process.
A Detailed Guide to Breaking in Your Brakes
There are 5 steps to breaking in your brakes.
Step 1: Start Driving and Speed Up To 60 MPH
Before starting to break in your brakes, you should think carefully about when and where to complete the process. You want to ensure that it’s done completely and safely.
The best time to complete this step is early in the morning, before a lot of people are out on the roads. Because you’ll be driving somewhat erratically, making abrupt stops and accelerating quickly, you want to make sure you don’t endanger yourself or anyone else on the roads. You also want to make sure you can complete the process without interruption, so the process is completed correctly.
Things that can interrupt this process include:
- Stop signs
- Changes in speed limit
- Curves in the road
Generally, long stretches of straight highway are devoid of the above factors, and therefore make a great location to break in new brakes. On the highway, you can drive at high speeds for long distances both legally and safely. You can be completely in control of when you need to brake, which is vital to completing this process correctly. Once you’ve determined the best time and location for breaking in your brakes, get on the stretch of road you’ve chosen and speed up to about 60 mph.
Step 2: Brake Quickly to Slow Down To 20 MPH
Once you’ve reached your target high speed of 60 mph, apply moderate pressure to your brake pedal. You should be pressing the pedal down about halfway to apply the proper amount of friction between your brake pads and rotor. This step is where you begin wearing down your brake pads and building up the transfer layer on your rotor.
As described above, while applying pressure to the brake pedal, the brake pads are squeezing your rotor on either side and the entire braking system is heating up. The surface of the brake pads is wearing off of the pads themselves and being deposited on the rotor. This creates the transfer layer. Don’t hold your foot on the brake while going 20 MPH, this can cause your brakes to overheat and disrupt the break-in process.
Step 3: Immediately Speed Back Up To 60 MPH
Now that you’ve reached your target low speed of 20 MPH, remove your foot from the brake pedal and start applying pressure to the accelerator. Once you’re cruising at 60 mph, your wheels and rotors are rotating at a high speed. Your brakes, which aren’t in use, are cooling down as friction between the rotors and brake pads is decreasing. The cooling and reduction of friction in your brakes combined with the high speed to rotation in your rotor allows an even layer of brake pad material to be deposited.
It’s important not to apply pressure to the brake pedal while your brakes are still cooling down in this step.
Step 4: Repeat Steps 2 and 3, 8-10 Times
Continue this controlled, deliberate system of accelerating and braking a minimum of 8-10 times. Do not come to a full stop at any point during this step of the process, and make sure to begin accelerating again as soon as you’ve reached your target low speed (20 MPH). Holding the brake pedal down while at a full stop will cause the brake pad to wear unevenly, resulting in an uneven deposition of the transfer layer on the rotor.
You may begin to smell your brakes after repeating this cycle several times. This is okay, but you can give your brakes a rest by cruising at your target high speed for a bit longer.
Step 5: Cruise at A High Speed Without Braking For 5-10 Minutes
This is where choosing a near-empty stretch of highway becomes important. Once you’ve completed your series of accelerations and decelerations, you should cruise at your high target speed (60 MPH) for 5-10 minutes without using your brakes at all. At this point in the process, your brakes are extremely hot due to frequent use and will readily deposit material onto the rotors if the brakes are applied. Braking during this step will cause the brake pads to deposit material unevenly. Cruising without using the brakes allows the brake system to fully cool down and the initial transfer layer to be completely and evenly deposited.
Once the transfer layer is completely deposited, you can use your brakes normally. This initial deposition of material from the brake pad onto the rotor will cause the brake pads to wear more evenly in the future than if a perfectly even transfer layer had not been immediately deposited on the rotors.
How to Tell If You’ve Successfully Broken in Your Brakes
You should perform a visual inspection of your rotors once the break-in process is complete. You should be able to see the transfer layer on your rotor, as it will be a different color than the rest of the rotor. If the transfer layer appears even all around the circumference of the rotor, it has been properly applied, and your brake pads should be free of any undetectable discrepancies in wear.
Above, we described a vibrating and shaking that occurs when your brake pads are worn down unevenly. Unfortunately, once you start to notice this, it’s too late for your brake system. You typically won’t notice or feel the shaking or vibrating until further into the lifespan of your brakes – once the opportunity to correctly break them in has passed.
When your brakes aren’t properly broken in, the brake pads will be worn unevenly, but to an undetectable degree. As you continue driving normally, the high and low spots on your uneven brake pad will become more and more extreme. Once it’s reached the point that you can notice the shaking and vibrating, the uneven wearing of the brake pads onto the rotor is too extreme to fix without resurfacing or replacing your rotors and getting new brake pads.
Once you’ve completed the above break-in process and checked your rotor for the transfer layer, it can still take up to 800 miles of driving to completely break in your brake system. For the next 800-1000 miles of driving, you will want to avoid abrupt stops to prevent overheating of your brake pads and rotors.
Some Do-Nots of The Break-In Procedure
The above steps should get you through the process of breaking in your brakes, but there are a few things you should not do, that we will reiterate here:
- Do not come to a complete stop
- Do not hold your foot on the brakes longer than necessary
- Do not brake too hard
Avoiding these three common mistakes will ensure that your brake pads don’t melt under extreme heat and friction. If you do these three things, you may risk glazing your brake pads.
Glazing occurs when the brake pads get so hot, that the material is liquified and re-hardens onto the surface of the pad as a hard, glassy layer. This significantly reduced the performance and lifespan of your brakes. Brake pads are intentionally soft and spongy, so they can gently squeeze the rotor while breaking. When the brake pads are hardened, they can crack and cause loud noises when they rub against the rotor while braking.
Alternative Methods to Breaking in New Brakes
The method described in this post is a common and widely accepted method of breaking in new brakes. But it is not the only way to properly prepare your brake system after getting your brake pads and/or rotors replaced. The method you choose to break in your brakes may depend on your location or the amount of time you want to spend on the process.
While details of the break-in process may change, the underlying principles above still apply.
The 30-30-30 Method
This method takes a bit longer than the method described above, which can also be called the 60-20-10 method. The 30-30-30 method involves:
- 30 repetitions of accelerating and braking, rather than the 8-10 repetitions recommended above
- 30 MPH as the target high speed and 10 MPH as the target low speed, rather than a 60 MPH target high speed and 20 MPH target low speed
- 30 seconds between each repetition of accelerating and braking
Breaking in Brakes in The City
When rapid acceleration and deceleration are not possible due to safety reasons and traffic laws, brakes still need to be broken in somehow. If, for some reason, you can’t escape the city to a long stretch of highway, you can still avoid depositing an uneven transfer layer onto your new rotors.
Many simply recommend driving normally while regulating the pressure you apply to your brake pedal:
- For the first 100 miles of driving with your new brakes, apply only very light pressure to your brake pedal to slow down. This requires slow and careful driving, to ensure that you don’t need to make any unexpected quick stops.
- For the next 250 miles of driving, use moderate pressure on the brake pedal. As with step 1, avoid making any sudden stops.
- Check your rotors to see if the transfer layer has been evenly deposited, as described above. If it has not been evenly applied, repeat step 2 for another 100-200 miles, then check the rotor again.
For an even more simplified method, some recommend simply making no abrupt panic stops for the first 500 miles. Panic stops are what can overheat your brakes and lead to an uneven deposition of material. Avoiding this, by driving slowly and cautiously, will lead to a proper, yet very slow, deposition of the transfer layer.
Breaking in New Brake Pads with Old Rotors
The break-in process is important whether you’ve replaced both your brake pads and rotors or just your brake pads. Brake pads are typically replaced more frequently than rotors are. There are some details to keep in mind if you’ve had new brake pads installed with old rotors.
New Brake Pads with Moderately Worn Rotors
If you’ve reached a point where you need new brake pads, but your rotors haven’t quite reached the end of their lifespan, the break-in process for your brake pads will be shorter. There is already a transfer layer on your rotor, so you just need to ensure that the brake pad begins wearing evenly. It will likely only take 200-300 miles to break in your new brakes, rather than 800-1000 miles.
New Brake Pads with Badly Worn Rotors
If both your brake pads and rotors are badly worn, you may elect to replace only your brake pads. While this is not recommended, you may still be able to get some life out of your rotors just by replacing the brake pads. When you do this, your brakes will require a very long break-in period. The break-in period for new brake pads with badly worn rotors is often up to 2000 miles.