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Komatsu Forklift Brake Master Cylinders - OEM and Aftermarket Replacements

Table of Contents

  1. Summary
  2. What Does a Komatsu Forklift Master Cylinder Do?
  3. What are the Symptoms of a Faulty Komatsu Forklift Master Cylinder?
  4. Where is the Master Cylinder Located on a Komatsu Forklift?
  5. How to Replace a Komatsu Forklift Master Cylinder
  6. Get Your New Komatsu Forklift Master Cylinder at Lift Parts Warehouse
  7. Takeaways


The master cylinder is a significant hydraulic brake device that can be found in a large number of Komatsu forklift models. When this device no longer works as it should, the brake response effectiveness of these vehicles is greatly reduced. Any Komatsu forklift master cylinder is directly related to the driver's safety and the people around the lift truck, so they must always perform at their best. That is why it is so important to learn how to judge when is the right time to replace it. With this in mind, Lift Parts Warehouse wants to show you how these devices work, their main faulty symptoms, and what you need to know when purchasing their replacements.

What Does a Komatsu Forklift Master Cylinder Do?

The master cylinder is responsible for making the brake pedal's force into hydraulic pressure. When the forklift driver wants to slow down, they will press on the brake pedal. This will set a series of mechanisms to move a piston inside the master cylinder. When the master cylinder's piston moves, it will raise the hydraulic pressure on the brake fluid inside it. This pressure will be distributed throughout the vehicle's brake system.

New brake master cylinder for Komatsu forklifts: 3EB-36-22700
Brake master cylinder for a FG20S-11 Komatsu forklift

The pressure from the hydraulic cylinder will activate the wheel brake cylinders and cause the lining material of the brake shoes to press against the inside face of the brake drums. This friction will slow down or stop the truck. The braking speed depends on how well the hydraulic cylinder works and how well all of the other parts of the brake system work together.

Generally, the main body of a Komatsu forklift master cylinder is made of cast iron, which makes its most resistant part. However, inside and outside this rigid body, we can find several elements. These are the most important ones:

  • The brake fluid reservoir. It's responsible for storing most of the brake fluid used in the brake system.
  • Pushrod. It's the parts that interact mechanically with the brake pedal. When the lift truck operator pushes down the brake pedal, the pushrod presses into the master cylinder, causing hydraulic pressure to increase.
  • The internal pistons. They are located in the center of the cylinder body and are separated by the springs.
  • The springs. They provide the counter force that puts the master cylinder pistons back in their original position once the brake pedal is released.
  • Rubber piston cups. They are located inside the cylinder body and help seal the pistons.
  • The reservoir cap. It is located at the top of the reservoir and helps keep the brake fluid from leaking.

If you want to see how these parts work together to active the hydraulic system of vehicle, check it out in the next video:

What are the Symptoms of a Faulty Komatsu Forklift Master Cylinder?

Lift truck drive pushing the brake pedal of a Komatsu forklift to test its master cylinder.
It's easy to know when a master cylinder start to fail

It is important to know when to replace the master cylinder on a Komatsu forklift. Knowing how to recognize a faulty brake master cylinder can prevent the safety of the forklift operator or those near the vehicle from being compromised. It is rare for these devices to break suddenly, so it would be easy to replace them when the first signs of failure appear. Below we will highlight the most prominent symptoms.

  1. Spongy Brake Pedal Behavior: If the forklift operator feels spongy or mushy when pressing down on the brake pedal, it is a clear sign that the master cylinder is not providing enough hydraulic pressure.
  2. Brake fluid leak: Brake fluid leaks typically occur when certain master cylinder seals fail. They are usually found where brake lines connect. It can also be due to a crack in the tank body.
  3. Brake fluid contaminated: If the color of the brake fluid changes, it may indicate that the seals or elements of the master cylinder are deteriorating for some reason. When this happens, the brake pressure may not be as strong as it should be, and you will probably have to press harder on the brake pedal to decelerate the vehicle.
  4. Brakes feel "grabby": If your Clark forklift brakes start to feel "grabby" or like they are engaging too early? It's another sign that the master cylinder is failing.

Where is the Master Cylinder Located on a Komatsu Forklift?

Komatsu forklift with its master cylinder location highlighted
Komatsu forklift master cylinder location

Locating the master cylinder on a Komatsu monster gas is not difficult. On most models of these vehicles, the master cylinder can be found under the operator's feet, just below the floor panel. Depending on the Komatsu lift truck model, the master cylinder could be found in front of the operator's legs behind the pedal panel. To be sure, it is best to first consult the user manual corresponding to your lift truck model. If you don't have the manual at your disposal, try to expose the brake pedal mechanism until you find the master cylinder push rod.

How to Replace a Komatsu Forklift Master Cylinder

Mechanic decoupling a Komatsu forklift master cylinder
Steps to change the master cylinder of a Komatsu forklift

  1. Remove the bottom panel of the Komatsu forklift to expose the brake mechanisms.
  2. Removal of the old brake fluid from the brake system.
  3. Decoupling the brake lines from the brake master cylinder.
  4. Remove the old master cylinder.
  5. Clean all connections.
  6. Put in the new master cylinder.
  7. Reconnect ehe brake lines.
  8. Refill the brake system with new brake fluid.
  9. Bleed the brake system.
  10. Test the brake response.

Get Your New Komatsu Forklift Master Cylinder at Lift Parts Warehouse

If you are looking for a new master cylinder for your Komatsu lift truck, there is no better place to get it than Lift Parts Warehouse. In the Lift Parts Warehouse online store, you will find a wide variety of master cylinders compatible with a huge selection of Komatsu forklift models.

We count on an "easy-to-pick" system to facilitate your shopping experience better than any other place. And thanks to our excellent delivery service you can get your order in just a few days.

We offer you some of the most attractive and competitive prices in the market. No, for nothing, we have been leaders in the distribution of forklift spare parts in the United States for years. If you want to know more about our price policy, please click here.

You can get many other Komatsu forklift parts at our online store. Remember, your shipping will be free if your order goes over $650. The Komatsu lift truck products that our customers most often request us are:

In addition, if you work with other forklift brands, you can also count on our services. We have a huge selection of replacement parts in our stock from brands such as Toyota, Nissan, Hyster, TCM, Clark, and many others.


The Komatsu forklift master cylinder is one of the most important components of many Komatsu lift truck models. They are constantly used to control the braking action of these vehicles. They convert the mechanical force applied to the brake pedal into hydraulic force that activates the brake shoes. They are indispensable for the safety of the operator or those around the truck. That's why, when you need a new Komatsu forklift master cylinder, do not hesitate to contact Lift Parts Warehouse services. With our brand new master cylinder, your Komatsu lift truck will be back performing at its best once again.

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