Brake Master Cylinder Reservoir Replacement Cost Estimate

Simply put, the brake master cylinder reservoir must be visually inspected to determine failure. If the technician notices the brakes feel spongy or the brake pedal sinks to the floor, he may attempt to bleed the brakes before determining where the leak in the brake system exists. In many cases, even when the reservoir can be replaced separately, the brake master cylinder and master cylinder reservoir will be replaced at the same time. This is most common when the brake fluid reservoir to master cylinder seal is deteriorated. If no brake issues are noted, the technician will note the location of any leaks or cracks, and recommend replacement of the reservoir, seals, or master cylinder and reservoir assembly.

Depending on the components being replaced, this can be as simple as removing the lid and placing a new lid on the reservoir, or it can be as difficult as replacing the master cylinder as a whole. The worst case scenario will require the brake master cylinder to be removed, so let's take a look at how that is accomplished. First, the technician will begin by draining the brake fluid from the system, especially since the new brake master cylinder will require new fluid and bleeding of air. Then, while the brake master cylinder is still firmly attached to the brake booster, the brake lines will be removed, and excess fluid will be caught with rags or a drip pan, ensuring that the brake fluid is not allowed to drip on any painted surface. Next, fasteners which attach the brake master cylinder will be removed, and the brake fluid level sensor and brake pressure switch will be disconnected if equipped. Afterwards, the new brake master cylinder with the attached brake master cylinder reservoir can be mounted, electronic switch connectors installed, and brake lines can be installed as well. Lastly, the reservoir will be filled with the appropriate grade of brake fluid, and the entire system will be flushed of the old brake fluid and bled of air before testing.

We recommend using the factory approved brake fluid for the vehicle being repaired, and not mixing any types of brake fluid. Also, the brake system should be flushed and inspected for obvious signs of deterioration, and repaired if necessary to prevent further failure. If the Entire brake hydraulic system is replaced, a new type of brake fluid may be used, but it must be at least the minimum standard of when the vehicle was manufactured.

Mixing brake fluid can lead to brake system failure due to congealing of the fluid within the brake lines. The different types of brake fluid, i.e. DOT3, DOT4, or DOT5 are meant for higher and higher braking demand, and will not always result in better braking performance. In fact, except for the most strenuous braking conditions, upgrading brake fluid will likely have no benefit.

Brake master cylinder reservoir replacement is an easy task given a good knowledge of hydraulic system maintenance and operation. The informed and experienced DIYer can tackle the diagnosis and repair of the brake master cylinder reservoir in a few hours, but proper bleeding and diagnostic procedures must be understood and followed. If the brake master cylinder must be replaced along with the brake fluid reservoir, or if diagnosing the cause of brake system inefficiency proves too difficult, have a professional tackle this job as a safety precaution.