How To Remove Brake Fluid Reservoir From Master Cylinder?

Dealing with a faulty brake fluid reservoir? This is the perfect article for you!

For many modern vehicles, the hydraulic clutch operates through a master cylinder. When you engage the clutch, hydraulic fluid from the master cylinder flows into the slave cylinder via a copper tube. If the slave cylinder malfunctions, fluid bleeding and leakage can occur.

This comprehensive guide will teach you how to remove the brake fluid reservoir from your car’s master cylinder.

Why Would You Need to Remove the Brake Fluid Reservoir?

The brake master cylinder reservoir, also known as the brake fluid reservoir, is typically constructed of a plastic polymer. Even though the plastic is made to be tough and last long, it can eventually become weak and break easily. When this occurs, brake fluid can leak through the cracks.

Remember, brake fluid soaks up water because it’s hygroscopic. Moisture can infiltrate the reservoir through the cracks and contaminate the hydraulic brake fluid. This contamination reduces the fluid’s boiling point, which can significantly diminish your vehicle’s braking performance.

Cracks in the reservoir aren’t the only reason you may need to replace the brake fluid reservoir. Sometimes the reservoir cap requires replacement due to damaged venting or a faulty diaphragm. When this happens, the cap’s moisture seal is compromised, leading to similar fluid contamination as with a cracked reservoir.

Removing Brake Fluid Reservoir from Master Cylinder: A Step-by-Step Guide

If you’re new to automotive repairs, this task might seem daunting. However, our guide is designed to assist everyone interested in removing the brake fluid reservoir from the master cylinder themselves. Simply follow the steps outlined below.

Thankfully, you won’t need much equipment to remove the brake fluid reservoir from the master cylinder. The essential tools for this task are:

  1. A vise
  2. A flathead screwdriver or a pry bar

Step 1: Raise the Hood

Find where the problem starts to start fixing it. Since the master cylinder is situated within the engine chamber under the hood, you’ll need to lift the hood. Be cautious when doing so, ensuring the hood doesn’t fall on your neck or head. Use the support rod to secure it in place.

Step 2: Locate the Master Cylinder

Next, locate the master cylinder. It’s typically positioned near the driver’s seat and mounted close to the firewall. The master cylinder is made of either metal or plastic and can be identified by the four hoses and brake line attached to it.

Step 3: Secure the Cylinder with a Vise

After discovering the master cylinder, use a vise to hold it in place. This will keep the cylinder steady and safe during the removal process. Failing to use a vise can make the procedure more difficult.

Step 4: Insert the Screwdriver or Pry Bar

With the vise in place, slide a flathead screwdriver or a pry bar between the brake fluid reservoir and the master cylinder. Be cautious and ensure the

tools you’re using are in good condition; using damaged tools can waste both time and money.

Step 5: Separate the Reservoir from the Cylinder

As you insert the screwdriver or pry bar between the cylinder and reservoir, gently apply pressure to nudge the reservoir apart from the cylinder. Once separated, you’ll notice a rubber seal that holds the two components together. Remove this seal as well. Great job, you’ve finished your task!

Troubleshooting Common Brake Fluid Reservoir Issues

In addition to removing the brake fluid reservoir, it’s helpful to be aware of common issues that may arise with this component. Comprehending these issues enables you to detect potential problems and take essential steps to maintain your braking system in optimal condition.

  1. Brake Fluid Contamination: As mentioned earlier, brake fluid is hygroscopic and can absorb moisture over time. This can lead to contamination and reduced braking efficiency. It’s crucial to monitor your brake fluid’s condition and replace it as needed to maintain optimal braking performance.
  2. Damaged or Worn Seals: The seals that connect the brake fluid reservoir to the master cylinder can deteriorate over time. If these seals are damaged or worn, they can allow brake fluid to leak, compromising your vehicle’s braking system. Keep an eye on these seals and replace them if necessary when removing the brake fluid reservoir.

Maintaining Your Vehicle’s Braking System for Optimal Performance

Your vehicle’s braking system is intricate yet surprisingly straightforward to maintain yourself.

Checking and fixing every part is important, such as the master cylinder, brake line, brake pads, calipers, and rotors. Your car’s manual should provide a recommended brake maintenance schedule.

It’s wise to examine your brake pads every 12,000 miles and change your fluid every 25,000 miles. These estimates vary depending on your vehicle and driving habits. A reputable auto parts store can determine the right brakes for your vehicle and perform more complex maintenance and repairs as needed.

Here are five essential steps to brake maintenance to ensure road safety:

1. Inspect Brake Pads and Rotors

Brake pads and rotors, which form the contact point between your braking system and tires, deteriorate more easily than other components and require frequent maintenance. Examine the quality and depth of the pads to ensure sufficient resistance. If you notice a need to depress your brake pedal further, a burning smell, or an increased stopping distance, check and replace your brake pads and rotors. To assess their wear at home, simply remove the tire.

2. Flush Brake Fluid

Brake fluid transfers pressure from the master cylinder through the brake lines and into the calipers, which then apply this pressure to the brake pads and rotors. Unfortunately, brake fluid attracts moisture, causing corrosion and reducing the fluid’s boiling point, which affects braking effectiveness. Check and change brake fluid every 25,000 miles. Cloudy or milky fluid indicates the need for replacement.

3. Bleed Brake Lines

Bleeding the brake lines helps remove excess air, which can reduce braking efficacy. Perform this procedure every 2-3 years during scheduled brake inspections by depressing the brake pedal while adjusting the bleeder valve.

4. Replace or Upgrade Brake Components

When necessary, replacing or upgrading brake components can enhance your vehicle’s braking system. Popular upgrades include heat-resistant slotted disc brakes or quieter, dust-reducing ceramic pads.

5. Overall Brake System Care

Proper care for your braking system involves avoiding factors that contribute to brake deterioration, such as carrying excessive weight, unnecessary or heavy braking, and wet weather conditions (also read: Why Brakes Squeak When Wet). Steering clear of these situations will improve your brakes’ performance and longevity, reducing the likelihood of brake failure-related incidents.


The brake system is a vital component of any vehicle. To maintain optimal control, it’s crucial to ensure that the brake fluid reservoir is functioning properly. However, when cracks develop in the reservoir or the cap needs replacement, it’s necessary to remove the reservoir from the master cylinder.

By integrating your automotive expertise with the insights shared in this article, we firmly believe that you can effectively remove the brake fluid reservoir from the master cylinder. In case of difficulties or uncertainty, seek professional help without hesitation. Keeping your vehicle’s braking system in important to maintain your safety and others’ safety.


1. Why Is My Brake Fluid Leaking From The Master Cylinder Reservoir?

Brake fluid leaks, especially from the master cylinder reservoir, can be quite concerning. The most common reason for this issue is a worn or damaged seal in the master cylinder, caliper, or wheel cylinder. These seals are vital to maintaining pressure in the brake system and preventing fluid from escaping.

As your vehicle ages, the seals may deteriorate, allowing brake fluid to leak. It’s essential to address this issue promptly, as a brake fluid leak can lead to decreased braking performance, putting you and others on the road at risk.

2. Should The Brake Fluid Reservoir Be Full?

Yes, it’s essential to maintain a full brake fluid reservoir to ensure proper functioning of your vehicle’s braking system. The fluid level should be within the designated minimum and maximum lines marked on the reservoir. If the level falls below the minimum line, air may enter the system, causing a spongy brake pedal and reduced braking performance.

However, don’t overfill the reservoir either, as this could cause the fluid to overflow when the brake system heats up, potentially damaging surrounding components. Regularly check your brake fluid level and top it up with the manufacturer’s recommended fluid as needed.

3. Can You Open The Brake Reservoir When Hot?

It’s not advisable to open the brake reservoir when hot. The heat generated by the engine and braking system can cause the brake fluid to expand, and opening the reservoir while hot may result in fluid spillage.

Moreover, spilled brake fluid can corrode nearby parts and pose a fire risk when exposed to heat. Instead, wait for the engine to cool down or check the brake fluid reservoir after your vehicle has been parked for a while to ensure a safe and accurate fluid level reading.

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