Re: 1955 Patrician Brakes

Posted by JeromeSolberg On 2021/9/14 15:06:04

I tried a 3/4" master out of Ford Courier with a 7" booster (also out of a Ford Courier IIRC), I put a post up with part #'s and pictures, you'd have to search back a while but it's there. I still have it stashed somewhere.

It DIDN'T WORK. The pedal force required was still too much. I had other people try it as well and they agreed. You are still off by a fair bit ( (5/8)^2/(3/4)^2 ) = 0.70, so you only had 70% of the standard braking force available. You would need a 1.25 or so pedal ratio to get back to where you were. Possible, maybe. But also the Ford Courier master cylinder was pretty small stroke, so that would be something to consider. In the case of brake fade might have to pump the brakes a lot.

At a 1" master you are at ((5/8)^2/1^2) = 0.40, or only 40% of the braking force available. You would need a 2.56 pedal ratio to get back to where you are.

Ross also points out that in some conversions of Studebakers that he's investigated the linkage, etc. was set up so the pedal could never travel far enough to actually "activate" the dual option, e.g. if one of the cylinder sections actually failed.

Recently I think the best way to go is to either move to DOT 5 or move to a low-vapor-absorption DOT 3 like Prestone MAX, and do things like in my earlier post about the "bladder cap", to keep moisture out when the car is sitting. That and frequent maintenance.

But I talked to some Packard people this weekend and they all said they used DOT 5, which I understand is what Kanter uses in their cars.

Kanter and Wilwood both sells Disc Brake conversions and I believe they are set up for the BTV, I would talk to them about it.