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JWL

Re: Manual brake conversion

#31

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May be a bit off topic, but is anyone familiar with brake master cylinders being boosted by the power steering pump? I recall seeing one of these boosters being installed on one of the car restoration programs. Maybe it was on one of the Restoration Garage episodes? One of these boosters may solve the space problem if the car already has power steering.

Posted on: 2021/5/1 12:13

We move toward
And make happen
What occupies our mind... (W. Scherer)

HH56

Re: Manual brake conversion

#32

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There may have been a hydraulic system installed on one of the car shows and I know they have also featured the Electroboost setups.

Craig's old Panther site featured the work done by his friend Paul adapting a hydraulic boost unit on a 56 Executive. No idea if the aftermarket places had them so readily available at that time because I think his was adapted from a Continental. At any rate he said it worked very well.

While the Hydro systems are much smaller than the vacuum booster and will most likely fit under the floor of a standard suspension car without too much issue, they still require a ratio or about 4:1 and not the 1:1 BTVs use that so many wanting modern brakes are trying to work around.

Posted on: 2021/5/1 12:57

Howard

Chris R

Re: Manual brake conversion

#33

Home away from home

Quote:

HH56 wrote:
Question I have is where are you going to mount and what type pedal? If there is enough room and you mount in the engine compt down toward the original location and adapt to use the bottom of the original PB pedal that will be 1:1 and converted by the new mechanism to 4:1. If you mount up higher near the air vent and connect to the pedal arm that might not provide enough stroke the way the stock pedal assy is suspended. If you install the 55 manual pedal and mount under the floor that will be around 6:1 and you would not need the extra linkage in the new bracket.

You're right. I keep flip flopping around trying to get to the bottom of this. Really, the best way to approach this is with the master under the floor. Assisted or unassisted, that arrangement will provide the best leverage.

I'll keep moving forward with this setup and see what I can figure out.

Quote:

JeromeSolberg wrote:
You can think of the master cylinder/slave cylinder relationship as a lever, with the lever ratio being the ratio of the areas. The smaller the area, the larger the pressure, but you have to make that up with a long stroke, just like in a long lever arm.
The Bendix Treadle-Vac has a 0.652" (some say 0.655") bore diameter, with a very long stroke, from what I can measure around 3". This is what allowed it to work with the small diameter vacuum booster, and be (marginally) acceptable in the case one lost vacuum.

I tried a Ford Courier dual master cylinder with it's 7" booster. It has a 3/4" bore size. The 7" booster barely fit down there, but all in all the installation looked great. I put some pictures up somewhere on another thread, I need to find it.

However, the pressure ratio is proportional to the square of the bore diameter (area=pi D^2/4) that means it has a pressure ratio of (0.655/0.75)^2 which comes out to about 75% of the original brake pressure.

It was NOT ENOUGH! I drove it and I had to push HARD on the pedal, and my neighbor was of the opinion it was not safe.

I have recently evaluated using the Wildwood TM1 externally mounted dual master cylinder. It has a 0.625" bore, but only a 1.3" stroke, so I don't think it would be acceptable, though I have thought about it.

Wilwood TM1 Master Cylinder, 0.625" bore

Yeah, with the placement of the original setup, and the 1:1 ratio, I think its pretty much impossible to get something to work safely and correctly.

Even for the people that have put a small booster where the original setup was, if vacuum vanishes, they're going to be in a hard place.

Quote:

JWL wrote:
May be a bit off topic, but is anyone familiar with brake master cylinders being boosted by the power steering pump? I recall seeing one of these boosters being installed on one of the car restoration programs. Maybe it was on one of the Restoration Garage episodes? One of these boosters may solve the space problem if the car already has power steering.

There was actually a video on Youtube where a 53 was up on a 2 post lift and the tech was showing the brake setup that they had installed for the customer. It was a GM hydroboost mounted under the floor and was tied into the factory power steering pump. It looked like it was very nicely done. I've tried looking for the video recently but I can't seem to find it for the life of me. If I do, I'll post it here.

EDIT: I found the video.

transmissionadapters.com/blogs/blog/glen-kohouts-1953-packard-convertible

Is Glen Kohouts a member here?

-Chris

Posted on: 2021/5/4 10:31

Chris R

Re: Manual brake conversion

#34

Home away from home

Update:

The pictures I posted earlier in this thread were from an expired ebay listing I found on google. I reached out to the seller to ask some questions about the setup and it turns out he still had the everything from that listing.

After talking back and fourth for last 2-3 weeks, I ended up purchasing the setup from him.

I do believe it to be a 55-56 TL manual clutch / brake setup based on all the Packard part plates I've looked at.

I've talked to numerous people on and offline regarding acquiring this setup, and everyone pretty much said that this setup was incredibly rare and very uncommon.

I had three different people tell me that in there 40+ years of playing with Packards, or parting them out, they had never seen this setup in person.

So, if this is what I believe it to be, I got pretty darn lucky.

Right now I'm in the process of putting up a 28x40 shop in my backyard, so I won't be able to really look into everything until all the dust has settled on this project.

The plan in my head is to figure out what will be needed to adapt this setup to work on my 53, see if I'm able to simplify the setup, and recreate it to help others. I'd really like to put this whole Treadle-Vac / single circuit master issue to bed once and for all.

Attached are some better pictures of the setup so you all can see what I'm working with. If anyone has any advice or suggestions I'd love to hear 'em.

-Chris

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