How to determine if I originally had manual or power brakes?

[swazzie]

I have searched through the forums without much luck and was wondering if anyone could explain to me how to determine if my car originally had manual or power brakes. I have a 1966 polar 500 which was originally a 383car. The power booster that is on the car does not look like the booster shown in the factory manuals and the master cylinder has been converted to a later 60's style 2 pot unit so it doesn't appear that these items will be of any help. Thanks for any info any of you can share.

 

[Toolmanmike]

Is there a number under the "capital D" on your fender tag? That line telld you what kind of brakes you have H, J, K, and L are power options. A photo of your fender tag (or build sheet if you have one) would help.

 

[I84885]

I have searched through the forums without much luck and was wondering if anyone could explain to me how to determine if my car originally had manual or power brakes. I have a 1966 polar 500 which was originally a 383car. The power booster that is on the car does not look like the booster shown in the factory manuals and the master cylinder has been converted to a later 60's style 2 pot unit so it doesn't appear that these items will be of any help. Thanks for any info any of you can share.

I may be mistaken but was under the impression that any car with a booster was considered power brakes and without booster is manual

 

[57fury440]

He has power brakes now. He is trying to find out if the car had them originally. It could have been converted.

 

[fury fan]

But regardless of what the fendertag and build sheet show, the pedal assembly could've been swapped.

Here is a manual-brake C-body with a power brake retrofit, using the original manual-brake pedal setup. There are extra lever-brackets to reduce the throw on the pedal, which spaces the booster out from the firewall. (this is not very common on a C-body, as I believe it was a field-retrofit thing)

In this pic below I've sketched how to identify a PB from an MB. (this is a Fusey clutch pedal setup but the other principles apply)

The upper red circle would be a pivot pin.
The lower red would be the pin where the power brake booster rod attaches.
The blue circle represents where a manual brake would attach to the master cylinder.

If the rod out to the brakes attaches about 3" or so down from the pivot pin - it's a MB pedal.
If the rod attaches like 5-6" away - it's for power brakes.

As the pedal needs to be in approx the same location for the driver, the bracketry for the power brakes is generally taller to get the pivot pin higher up.

It's all a matter of proper leverage for the driver's leg. The power-brake system doesn't need as much leverage.

 

[Gerald Morris]

But regardless of what the fendertag and build sheet show, the pedal assembly could've been swapped.

....

If the rod out to the brakes attaches about 3" or so down from the pivot pin - it's a MB pedal.
If the rod attaches like 5-6" away - it's for power brakes.

As the pedal needs to be in approx the same location for the driver, the bracketry for the power brakes is generally taller to get the pivot pin higher up.

It's all a matter of proper leverage for the driver's leg. The power-brake system doesn't need as much leverage.

Sooo true! I had to transfer the manual brake pedal and bracket from the wreck of our '66 Newport to our '68 before I could get good leverage on the manual master cylinder, no ifs, ands or buts. Once done, All was/is well! BTW, I use the piston rod from the old single pot cylinder w a dual pot Bendix clone now, and this works nicely too, for those considering an upgrade on pre-67 systems.