The Average Cost for a Master Cylinder Replacement Is $150 to $550, Depending on Whether You Go to a Mechanic or DIY.
This price range is based on the national averages for all vehicles, and it does not consider fees, taxes, your vehicle’s make and model, or other factors. Along with a master cylinder replacement, people sometimes get related repairs or maintenance, such as rotor and brake pad replacement. For a more precise estimate based on your vehicle’s make, model, and location, you can use the RepairPal Fair Price Estimator.
Cost at the Mechanic: $300-$550
Parts: $150 to $300
Labor: $150 to $250
The brake master cylinder converts the physical force from your foot pressing on the brake to hydraulic force that can work to slow or stop the vehicle. With older cars, trucks, and SUVs, replacing the master cylinder takes an hour or two. This part is less accessible with many newer models, so a mechanic could take up to eight hours to replace it. Master cylinders are normally designed to last as long as the rest of the vehicle, so people usually only have to replace them if they become damaged or contaminated.
Cost to DIY: $150-$350
- Difficulty Level: Intermediate
- Parts Needed:
People with the tools and the mechanical knowledge needed can often save money by replacing a master cylinder themselves. To be successful, you should have some experience with DIY vehicle repair and a variety of tools, not only to replace the master cylinder itself but also to bleed the brake fluid system afterward. Aside from removing the cap on the master cylinder reservoir, any time the brake fluid system is opened (such as caliper or wheel cylinder replacement), the system must be bled to ensure there are no air pockets in the fluid, which can affect braking performance.
What Is Master Cylinder Replacement?
The brake master cylinder is responsible for converting brake pedal force into hydraulic pressure that is evenly applied to all four wheels. Most systems use a proportioning valve to split the hydraulic fluid pressure for the front brakes and the rear brakes.
What Does Master Cylinder Replacement Include?
Master cylinder replacement includes several steps. First, you or an experienced mechanic would remove the brake fluid from the brake fluid reservoir using a draining kit or a siphon. Then, you or the mechanic would dispose of it according to your local regulations. Be careful as brake fluid is highly corrosive to vehicle paint, so even after you drain all the fluid from the reservoir, it’s still a good idea to utilize some sort of fender cover… even if it’s just an old towel. Once the fluid has been removed, disconnect the brake lines using an appropriate line wrench to prevent damaging the fittings. Disconnect any sensors attached to the brake master cylinder, and then remove the bolts (there are usually two) attaching the master cylinder to the vehicle’s firewall.
Install the new brake master cylinder in reverse order, and then follow proper procedures to bleed the brake fluid system to expel air from the lines. To bleed the brakes, you will usually need to jack up the vehicle, remove the wheels, and have one person apply pressure to the brake pedal while another person opens the bleeder screw located at each caliper or wheel cylinder. Top off the brake fluid reservoir and ensure the brake pedal builds adequate pressure, and then test drive the vehicle to verify the master cylinder replacement was successful,
What Happens If You Don’t Get a Master Cylinder Replacement?
Failing to replace a faulty, damaged, or contaminated brake master cylinder could result in a brake system failure. If you notice a soft, low, or mushy brake pedal, there’s a good chance that the master cylinder is going bad. This alone will lead to longer-than-expected braking distances and increase the likelihood of a crash. A completely failed brake master cylinder will apply no brake pressure to the wheels. If this happens while driving, you can still stop the vehicle by using the parking/emergency brake level or pedal, which applies brake pressure using a mechanical connection rather hydraulic fluid. If your vehicle has an electric parking/emergency brake, press and hold the button until the brakes start to apply.
How Often to Get a Master Cylinder Replacement
A master cylinder can last from 60,000 to 200,000 miles or longer. People who drive in traffic and use their brakes often usually need to replace their master cylinders sooner. Master cylinders for clutches have shorter lifespans than those for brakes. You can consult your owner’s manual for more detailed information about replacing your master cylinder. Use the FIXD OBD2 sensor to keep your vehicle’s maintenance on schedule.
Common Symptoms You Need to Get a Master Cylinder
Replacement
- A brake pedal that sinks to the floor by itself
- A pedal that feels soft or mushy under your foot
- Leaking brake fluid
- Low brake fluid levels
- An active brake warning light
- Dark brown or black brake fluid that should be clear
- A car that drifts to one side of the road when you use the brakes
- Uneven brake pad wear
If you notice any of these symptoms, take your vehicle to a repair shop immediately. If your brakes aren’t working properly, have your car towed instead of risking a drive.
Related Maintenance Services
People can often get a variety of different services performed at the same time as a master cylinder replacement:
- Tire rotation
- Tire balancing
- New brake shoes and drums
- Tire rotation
- An oil change
Get the FIXD Sensor and free app to follow a convenient, customized maintenance schedule based on your vehicle’s mileage, make, and model. FIXD sends automated maintenance alerts straight to your smartphone, helping you to remember brake pad replacements, master cylinder replacements, oil changes, tire rotations, and more. It can even keep track of your tire tread, battery, and windshield wiper life to help make sure your car works smoothly. Get FIXD today to take much of the stress out of car care and save money. It’s that simple.
At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.
