Mercedes-Benz GLB35 AMG Brake Master Cylinder Replacement Costs

What is the brake master cylinder and how does it work?

The brake master cylinder has a piston that pressurizes fluid in the brake lines to each wheel cylinder as you apply force to the brake pedal. That pressure moves the pistons that are in the wheel cylinders. As the pistons in those wheel cylinders move, they force the brake pads or shoes tightly against the rotors or drums allowing the car to stop quickly.

The size of the pistons in the master cylinder and in the wheel cylinders are carefully selected when designing a car. This allows drivers to apply moderate pressure on the brake pedal when stopping, but creates tremendous pressure applied at the wheel cylinders. A car can then stop quickly even at high speeds. Depending on how much force is applied to the brake pedal, the pressure in a car’s brake lines will typically be in the range of 800 PSI to 2,000 PSI.

When to replace the master cylinder?

External fluid leaks. There should be no fluid visible on the external surfaces of any portion of the master cylinder or the plastic fluid reservoir.
Low, slowly falling, or spongy brake pedal. Faulty internal seals on the piston can cause internal leaks and also seepage of brake fluid into the power assist brake booster. Internal leaks will typically be accompanied by a low pedal, a spongy brake pedal, or a pedal that slowly sinks as you maintain pressure. In all cases, you will experience reduced braking abilities.
Discolored brake fluid. No brake fluids, other than those specified for the year, make, and model, are fully compatible with a car’s internal rubber seals in the master cylinder. Discoloration of brake fluid can also occur due to moisture and particulate contaminants in the fluid.
Warning lights on the dash. If the brake system warning light illuminates, there are several potential causes but failure of the master cylinder is in the list of causes that would have to be investigated.

How do mechanics replace the brake master cylinder?

On vehicles with power brakes, the master cylinder is bolted to the metal housing of the power brake booster. There is usually an electrical plug connecting to a brake fluid level sensor on the master cylinder reservoir and that plug must be disconnected.
Once all steel brake lines are disconnected from the master cylinder, the master cylinder is unbolted from the brake booster and removed from the vehicle.
The new master cylinder must be bench-bled to expel air from internal passages that contain the piston. Then the new master cylinder is bolted to the brake booster and the brake lines are reattached. The electrical plug for the fluid level sensor is reconnected.
Whenever a new master cylinder is installed, brakes lines to wheel positions must be bled to remove air, old fluid and contaminants. If your vehicle is equipped with anti-lock brakes, the mechanic may use a bidirectional scan tool during brake bleeding to actuate the ABS pump, thus ensuring that all air is removed from the complex valving in the ABS system.
All brake line connections that were removed during the master cylinder replacement are inspected for any leakage and the vehicle is road tested to ensure normal operation of the brakes.

Is it safe to drive with a master cylinder problem?

No, any fault in the master cylinder, which is part of the braking system creates a safety risk. A fully operational brake system is essential to quickly stopping your car. Driving a vehicle isn’t safe, if the master cylinder is leaking or has other faults, as braking distances might be longer than normal. The braking system on a vehicle is among the most important safety systems and must be fully functional to safely drive your vehicle.

When replacing the master cylinder keep in mind:

The master cylinder is only one component of many in a vehicle’s braking system. During replacement of the master cylinder, all vehicle braking system components should be inspected to ensure maximum braking power is available.
The amount of friction material remaining on the brake pads and brake shoes should be verified.
Brake lines and flexible rubber hoses at each wheel position should be inspected for corrosion and deterioration.
The power brake booster should be evaluated to ensure that power assist is working properly.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee

Meet some of our expert Mercedes-Benz mechanics

Real customer reviews from Mercedes-Benz owners like you.

Excellent Rating

(8)

Rating Summary

SEE REVIEWS NEAR ME

Frank

16 years of experience

31 reviews

Request Frank

by mike

Mercedes-Benz 450SL V8-4.5L - Brake Master Cylinder - Downers Grove, Illinois

he was on time ,polite ,professional.did the work quickly .work was done correctly..my car is difficult to work on.small car with no room to maneuver but he was able to get inside and get it done.

David

37 years of experience

195 reviews

Request David

by Toi

Mercedes-Benz ML350 V6-3.7L - Brake Master Cylinder - Los Angeles, California

David was able to come in and correct the problem made by my old mechanic. Now my vehicle is fixed and no more worries with my brake and power steering pump.

Arturo

28 years of experience

303 reviews

Request Arturo

by Romeo

Mercedes-Benz 380SL V8-3.8L - Brake Master Cylinder - San Diego, California

Did a great Job.

Rocco

23 years of experience

302 reviews

Request Rocco

by Russell

Mercedes-Benz 300SD L5-3.0L Turbo Diesel - Brake Master Cylinder - Newport Beach, California

Rocco was fantastic!

Mercedes-Benz GLB35 AMG Brake Master Cylinder Replacement at your home or office.

Estimate price near me

Brake Master Cylinder Replacement Service

How much does a Brake Master Cylinder Replacement cost?

On average, the cost for a Mercedes-Benz GLB35 AMG Brake Master Cylinder Replacement is $493 with $283 for parts and $210 for labor. Prices may vary depending on your location.

What is the brake master cylinder and how does it work?

When to replace the master cylinder?

How do mechanics replace the brake master cylinder?

Is it safe to drive with a master cylinder problem?

When replacing the master cylinder keep in mind:

Meet some of our expert Mercedes-Benz mechanics

Excellent Rating

Rating Summary

Frank

David

Arturo

Rocco

Excellent Rating

Rating Summary

Recent articles & questions

Car acts like it's starving of fuel.

My 2013 Mercedes benz c250 ac won't work, it blows hot air and the ac button light flashes red three times and then turns of

My nissan xtrail will crank but it wont start. I've bought a starter, spark plugs, fuel filter and a relay.

How can we help?