Brake Power Booster

My car is an early 71. (Nov 70 Build date) Original power drum automatic. Future Power Disk 4 speed.

The original pedal for my car has the nub on the pedal bar about an inch lower than the nub on the manual pedals I have. The plunger on my power booster hits too low to attach to the pedal shaft.

Were there 2 different boosters available for 71? How do I get the right part for this brake conversion?

View attachment 11140

My car is an early 71. (Nov 70 Build date) Original power drum automatic. Future Power Disk 4 speed.

The original pedal for my car has the nub on the pedal bar about an inch lower than the nub on the manual pedals I have. The plunger on my power booster hits too low to attach to the pedal shaft.

Were there 2 different boosters available for 71? How do I get the right part for this brake conversion?

Click to expand...

Sorry...I am confused.

For the record, your car originally had(Select 1 per line):

Brakes: Power/NonPower Brakes

Drum all 4/ Disc Front, Drum Back

Trans: Automatic/Manual

=======================

I believe you are trying to accomplish:

Installing new pedal set(clutch/brake) to accommodate your 4 Speed. However, you have an issue with the brake attachment.

Are you sure you have the correct pedal set?

Several members have done this. I suspect it will be a matter of time. Although, early models and late models do have their eccentricities.

You will need to get a pedal off an automatic with power brakes and just cut the pedal pad for a 4 speed car or not for an automatic. That was how I did mine and replaced the bushings while I was at it. I have one if you need it.

I had four wheel drum, I bought a power brake pedal off of ebay and swapped it out. It was a PITA to do it but it works well. Also bought the power booster assembly with brake reservoir from Rock Auto. the brake lines under the hood had to be 'modified' to meet the reposition of the reservoir. Also I purchased the factory spindles for the front disks and the lines had to be modified for the calipers. The rotors from the front are slotted and drilled and for the rear I bought another kit (master power brakes) for the disks with the same type of rotors. The biggest issue with the rear setup for me was the emergency brakes adjust and the initial adjust for the calipers, from what the literature said they were GM types brakes. The fronts were easy aside from the brake lines and pedal installation.

The replacement pedal shown is for a manual brake car. If you just swap your original power brake pedal into the replacement set up you will also need to add the additional bracket for the booster to bolt to at the firewall that must be attached to the complete assembly.

Thanks, Jay

My car is an early 71. (Nov 70 Build date) Original power drum automatic. Future Power Disk 4 speed.

The original pedal for my car has the nub on the pedal bar about an inch lower than the nub on the manual pedals I have. The plunger on my power booster hits too low to attach to the pedal shaft.

Were there 2 different boosters available for 71? How do I get the right part for this brake conversion?

Click to expand...

Sorry...I am confused.

For the record, your car originally had(Select 1 per line):

Brakes: Power/NonPower Brakes

Drum all 4/ Disc Front, Drum Back

Trans: Automatic/Manual

=======================

I believe you are trying to accomplish:

Installing new pedal set(clutch/brake) to accommodate your 4 Speed. However, you have an issue with the brake attachment.

Are you sure you have the correct pedal set?

Several members have done this. I suspect it will be a matter of time. Although, early models and late models do have their eccentricities.

Click to expand...

From your questions. 4 wheel drum, Power brakes, automatic

You will need to get a pedal off an automatic with power brakes and just cut the pedal pad for a 4 speed car or not for an automatic. That was how I did mine and replaced the bushings while I was at it. I have one if you need it.

Click to expand...

That is what I did years ago too. The pedal that came on my car has the pad trimmed in width. My question is why do the manual pedals have the nub in different location? Are the pedals with the high nub from a 73 wih a different booster? Are they from disk cars, that had a different booster? Are the boosters interchangeable on all 71-73 power brake cars? Obviously with the higher nub you will get shorter plunger travel on the brakes.

Yes, I can always use my trimmed manual pedal, I am just unsure why the other pedals won't work.

Different vacuum booster for power disk vs. vacuum assist drum

71 -3 's had

power disk

OR

manual drum

That is the reason for 2 different pedal pin locations

Don