Tech Talk with Master Power Brakes

How to Properly Install a Power Brake Booster in 8 Steps

Posted by Master Power Brakes Team on Nov 15, 2019 5:30:00 PM

If you want your classic car to perform at its best, the manual brakes have got to go.

You can still honor the style and integrity of your classic car while improving it's stopping power, performance, and your level of comfort. 

Although some might leave this job to the professionals, installation is a cinch when using quality parts. Follow the steps below to equip your vehicle with all the right components and start enjoying the benefits today.

RELATED: Do I have Power Brakes or Not? 


Power Brake Booster

1. Gather Your Parts

Whether your car came with power brakes as an option, or not, greatly influences which parts you will need for this upgrade. Early 60s cars that were only sold with manual brakes may need a new pedal assembly, proportioning valve, and dual reservoir master cylinder in addition to the power brake booster, for example. The specialists at Master Power Brakes are happy to help you figure out exactly what conversion parts your platform will need.

For most power brake booster conversions, you may need:

  1. 1. Single or dual diaphragm power brake booster

  2. 2. Dual reservoir master cylinder

  3. 3. Proportioning valve

  4. 4. Pedal assembly

  5. 5. Super DOT 4 Brake Fluid

  6. 6. Vacuum hose

  7. 7. Fittings

If your vehicle has a high-performance cam that reduces vacuum pressure, you may also need a Silent Drive Vacuum Pump to deliver vacuum to the booster.

RELATED: Do You Need a Silent Drive Vacuum Pump?

Check through all the parts you bought for this project, comparing their item lists to the parts in the box. Become familiar with what each part is and where it will go in the finalized installation to make this process much easier and less time consuming.

2. Remove the Old Master Cylinder

With all the organization and safety considerations out of the way, it is time to remove the old master cylinder by following these steps:

  1. Remove the fluid from the master cylinder and discard
  2. Disconnect the hydraulic fluid lines and set to the side
  3. Loosen and remove the nuts securing the master cylinder
  4. Carefully remove the master cylinder without dripping any remaining brake fluid

If replacing the master cylinder with a new one, throw the old one away.

3. Disconnect the Pedal Assembly

Depending on the application, you will likely need to disconnect the pedal assembly from the firewall. If you plan to use the existing brake pedal assembly, mark the height of your brake pedal before removing any parts. You can do so by using a wooden block to hold the brake pedal at the ideal height. Also, consider taking a couple photos showing the stock height for comparison purposes later on.

There are applications that won’t require anything be done to the pedal while there are others that are going to require a complete replacement of the brake pedal. On the other hand, some might be in the middle and only require that a new hole be drilled. Just like any installation, it is best to completely read through the instructions to see what is needed.

4. Prepare the Firewall for the Booster

Just like the above with the brake pedal, the level of what needs to be done with the firewall can vary. Some cars are simple: remove the master cylinder and then install the new brake booster assembly. Other vehicles are going to require a bit more work. This work is usually nothing more than drilling a couple of holes that weren’t there or enlarging some that are already there.

Not to sound like a broken record but please, read through the instructions in advance of doing anything. It will save a bunch of time down the road. The instructions are always available on our website with each part listed and our technical representatives will gladly discuss what is needed for your application.

If there is no room at the firewall, or you would like the booster located elsewhere, consider a remote brake booster instead. These remote units can also preserve the authentic look of classic cars without compromising on performance.

5. Install the Power Brake Booster Assembly

With any modifications or changes necessary to the firewall, the brake booster can be mounted to the firewall. Use the included hardware to mount the power brake booster to the firewall and confirm it is secure.

With the pushrod through the firewall, adjust the length of the pushrod to it’s attaching point on the brake pedal. Some pushrods will have the ability to adjust via threaded pushrod while others will require the change of the pushrod. The end goal is to get the pedal positioned to where it is comfortable to the driver.

Run a vacuum line from the engine or standalone pump to the brake booster using any fittings needed to properly secure the line. 

6. Mount the Combination Valve 

In some applications, this step will be skipped. For cars that are staying with a drum brake scenario on all four corners but upgrading to power brakes will not require the use of a Combination Valve while a vehicle that is getting converted to disc brakes at the same time as the power conversion will require this addition. 

With the Combination Valve mounted, it is necessary to adapt any brake lines from the existing vehicle into the new valve. This may require a simple tweak to the lines but it also might require making new lines. Regardless, make sure all of the flares look good to prevent any leaks once pressure is put to the system.

7. Bleed the Brake System

With everything hooked up properly, it is time to bleed the brakes and optimize the pressure in the system. Before bleeding the entire brake system, we strongly recommend that the master cylinder be bled by itself. This can be done using our Syringe Bleeding Kit which is included in every power booster system that we sell. Once that has been completed, the rest of the brakes can be bleed.


READ: Why is it Important to Bleed the Brakes?


To bleed the brakes, bring in someone to help and follow these steps:

  1. 1. Top off the master cylinder reservoir with brake fluid

  2. 2. Start at the far corner and jack up the car

  3. 3. Remove the tire to access the brake components

  4. 4. Have your helper press down the brake pedal to the floor and hold it there

  5. 5. Crack open the bleeder screw at that corner

  6. 6. Wait until bubbles stop coming out of the line

  7. 7. Tighten down the bleeder screw

  8. 8. Repeat at every corner of the vehicle

As you go through the brake bleeding process, keep an eye on the fluid level in the reservoir, topping off as you go to keep it from reintroducing air into the system.

8. Check the Vehicle Operation

With everything installed and bled, the vehicle can now be driven and checked for proper operation. When doing this, take it easy to begin with. It is better to find something was missed at slow speed versus high speed.

Classic Cars

Once comfortable with the installation, enjoy your work and how much easier it will be to drive your classic car. Better yet, how much easier it is on you to stop!!

Getting Started in Installing a Power Brake Booster Yourself

As long as you have the right parts, tools, and know-how on your side, you can install a power brake booster conversion yourself. If you do not feel confident, however, a professional automotive technician can help you out.

You can also receive advice and support from the specialists at Master Power Brakes. Just give us a call at 1-800-472-4181 or fill out our online form to start learning how to treat your classic car to a power braking system.


Up Next: Converting to Power Brakes, Part 1: Why Booster Size Matters



Give us a call at 1-888-249-9425 and we’ll  be glad to answer any questions you might have.  The call is on us, so what are you waiting for?



Topics: How To Series, Tips and Info, Brake Boosters

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