Do I Have Power Brakes or Not?

I recently overheard an exchange taking place at a car show about whether or not you could make drum brakes into power brakes.

“Aren’t drum brakes always manual and disc brakes always power?” one fellow asked.

“That’s right. It’s why they have disc brake conversion systems,” a second fellow chimed in.

“Whoa, not so fast!” I said, stopping to jump into their discussion.


On one side, you have brakes that have no power assistance to the pedal, which we call manual brakes. On the other side, there are brakes with power assist, which make the pedal easier to depress, otherwise known as power brakes. A classic or hot rod car can have manual disc brakes or power-assisted drums.

“I thought a power booster was required equipment with disc brakes,” said one of my new buddies.

“No, is the short answer. Even though a power booster gives you a good pedal feel, manual disc brakes work fine,” I explained.

The real difference between power and manual brakes is whether or not the master cylinder has a power brake booster attached. Simply put, a power booster helps assist the master cylinder piston to apply force when you press the brake pedal.

All the brake hardware at the wheels will be the same, power or manual.

The booster is typically using vacuum pressure from the engine or a vacuum pump to help you apply pressure to the brake pedal. The reason people like a power booster is that you use less foot pressure on the pedal to get firm braking action. Originally presented as a new car feature “for the ladies,” the addition of a power booster meant you didn’t have to use every last ounce of leg power on the brake pedal to stop on a dime.

Converting your classic or street rod to employ a power booster along with a new master cylinder (replacing your current manual master cylinder) is a simple bolt-in installation.

Safety First: Dual Master Cylinder

Many cars prior to the 1970s used a single reservoir master cylinder. This is not the safest of situations. If a master cylinder should fail and there is only one line and reservoir, you will effectively lose brakes on the entire vehicle.

With a dual reservoir master cylinder, you have the security knowing that after converting with one of our kits, the front and rear braking systems on your car are completely separate from one another. It doesn’t matter whether or not your car came with a single or dual reservoir master cylinder to begin with, we have safety in mind in our conversion kits and always provide a dual reservoir master.

Upgrading to a dual reservoir master cylinder should be the first upgrade you make if your car is a daily or frequent driver and is currently equipped with a single reservoir master cylinder.

Article Courtesy of: Master Power Brakes

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39 Responses to “Do I Have Power Brakes or Not?”

  1. Terry

    There was also Hydra-boost that ran off the power steering pump used in early GM diesel cars.

  2. Joe

    How much would ir coast me to convert my 54 chevrole pickup to power brakes?

  3. Roger Kaufman

    I have experienced the same thing after adding a dual master cylinder to my non power brake car.

  4. Raoul Somers

    Nice very interesting Thanks Raoul

  5. Joe

    I just purchased à 1954 truck with no power breaks. How much should I expect to have it converted to power breaks?

  6. Willie Perry

    I have a 1966 mustang :I can’t get all the air out of the system after converting to disc brake front and rear.any help would be greatly appreciated


    I have seen a Valient which was absolutely stock had disc front brakes and not power brakes.

  8. Wayne A Schirner

    I want to upgrade my 1954 Chevy 3100 pickup to power disc brakes. Some kits I see say they can't be used on vehicles with a manual transmission. I also see that comment with dual chambered master cylinders. What are my options, since I have a manual transmission?

  9. Janedon (my fem name)

    Yup--I've had total brake failure on Older cars probably 1/2 dozen times & things got harry a few times -Including having to drive into a ditch to avoid a truck--One doesn't Need power brakes but that second Reservoir is very important-

  10. Robert Harvey

    I think a better terminology would be twin piston master cylinder, the reservoir in some cases whether twin or not could be irrelevant.