Packard Forum Index » Modification Discussion

This thread describes the new modern brake booster and modified stock pedal I am using on my Panther Project.

The booster is a new Master Power Brakes (MPB) #1007 7IN dual diaphram one. As you will see, it is mounted high on the firewall above the stock air vent and below the cowl lip. I am rewiring the whole car using a Painless brand generic wiring kit for large vehicles (same as KevinAZ used on his 55 400), so the holes in the firewall for the stock wiring harness are not needed, but YMMV.

The modified pedal will be described in the next post.

Cutting the holes for the MPB:




After the center hole was cut, four holes for the threaded studs on the back face of the booster were drilled and the booster trial mounted.




Inside view with stock 1956 Packard brake pedal assembly:

In order to get the required 4:1 pedal leverage needed by the MPB booster, I relocated the stock pivot brackets up the inside of the firewall near the external cowl lip. I cut down the pivot bar left side (Wilwood clutch pedal on the left of the picture):

I made a mockup using some bendable steel flat and duct tape. I had my local machine shop duplicate the dog-leg bends with welded 1/8IN steel "U" channel.



The pedal is in exactly the stock position and distance from the toe board. The pedal leverage is exactly 4:1.





Here is a closeup of the pivot thru bolt used to attach the MPB threaded actuator rod and heim end to the modified brake pedal arm:

I decided that the firewall was too ugly to be looking at later with all the various size unused holes and patch panels:



So I made up a pair of "skin panels" out of 16GA flat sheet stock to make it pretty. Left (driver) side shown:




The top unused hole is for the wire to the electric wiper motor and the bottom hole is for the cable to actuate the vent flap control.

Later, the MPB, etc will be unmounted and the skin panel will be edge welded in place and then painted the same color as the body, whatever that is.

Comments and questions welcome.

Craig

Craig, I really like this set up and your peddle design a thousand times more than the first test cutting a 56 peddle etc. Great work

Clever and very nice work. However, i have to ask: Does the extended pedal have enuf travel (before hitting floor board) to bottom out, or at least very nearly bottom out, the master cylinder.
Now i'm fully confident that Craig has the any pedal travel issues well considered, but maybe the removeabl toe board needs to be recessed????

PackardV8 Quote:

Keith, a good question. I will not know for certain until I get the correct disc/disc MC installed, plumbed and system bled, but I am very confident my arrangement will have sufficient pedal travel. The reason is my experience with the MPB #1001 (#1007 predecessor) booster in my 55 Pat and how much travel it has to fully engage. Also, the height of the pedal above the floor is adjustable with the threaded actuator rod in the MPB booster and threaded heim end, so that could provide more travel, if needed.

I will not be using the original toe plate, but I will fab one up out of 16GA flat sheet metal.

Craig