Brake Pedal Assembly

[dme922]

Is there any difference in a manual and power brake assembly? If so what is it? I switched my truck to power brakes and got the booster bracket from a forum member but the connecting rod is about an inch from the peadal. I can get it connected but it puts my pedal to close to the floor.

[Mr Handy]

I don't think there is a difference, the push rod should be adjustable so that you can adjust the pedal location. the power brake pedal sits closer to the firewall because the bore in the master is larger and requires less travel to move the same amount of fluid.

double check the service manual for the proper pedal location I think it says how many inches off the firewall it should be.... I'm sure someone else will chime in as well.

[Keith Seymore]

Normally there is a difference in pedal ratio between manual and power brakes.

The '69 and '70 charts that I have do not have that level of detail, but the 71 and 72 charts show around 6:1 for manual and 3.5:1 for power systems.

K

[dme922]

Originally Posted by Keith Seymore

Normally there is a difference in pedal ratio between manual and power brakes.

The '69 and '70 charts that I have do not have that level of detail, but the 71 and 72 charts show around 6:1 for manual and 3.5:1 for power systems.

K

I had the adjustment on the rod out all the way and still lacking about an inch. How far should the brake pedal arm be from the pedal arm bump?
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[LockDoc]

Originally Posted by dme922

I had the adjustment on the rod out all the way and still lacking about an inch. How far should the brake pedal arm be from the pedal arm bump?
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1/2" - 1" from the bump stop. Here is an OLD thread that discusses the problem.

http://67-72chevytrucks.com/vboard/s...d.php?t=151551

LockDoc

[70STOVEBOLT]

I used the stock manual brake/clutch pedal assembly and just added a booster and the correct push rod. I even used the stock manual drum/drum master cylinder, and have not had any issues. Then I removed the clutch pedal from the assembly when I switched to an automatic.

[Mike C]

Originally Posted by Keith Seymore

Normally there is a difference in pedal ratio between manual and power brakes.

The '69 and '70 charts that I have do not have that level of detail, but the 71 and 72 charts show around 6:1 for manual and 3.5:1 for power systems.

K

What he means is the power brake rod connects up higher on the brake pedal than the manual rod. If you are trying to use the same hole on the pedal, that's wrong.

[dme922]

Originally Posted by Mike C

What he means is the power brake rod connects up higher on the brake pedal than the manual rod. If you are trying to use the same hole on the pedal, that's wrong.

So were the pedal assemblies the same but the whole was just a bit higher?

[dme922]

The pedal assembly was for an automatic set up also. It just didnt have power brakes originally.

[Hart_Rod]

Originally Posted by Mike C

What he means is the power brake rod connects up higher on the brake pedal than the manual rod. If you are trying to use the same hole on the pedal, that's wrong.

I think that's backwards. I think the power brake rod should be lower than the manual. Take a look at this:

http://www.mpbrakes.com/techtalk/how...ng-pedal-ratio