Packard Forum Index » Modification Discussion

This photo shows the sheet metal protection for the system.

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Is your connecting link for the stepped pushrod between pedal rod and booster something commercial or did you make it?

I made something similar with my conversion in the 56 but am not happy with the setup. My link is too hard to adjust and there needs to be changes made with either the master itself or its almost vertical position or the pedal ratio obtained by modifying the pedal to have the take off higher and using a bellcrank in the vent hole to change direction. Currently my pedal is too sensitive -- as bad as or worse than the Treadlevac. Since I find it difficult to work on the car anymore to refine it or change the booster to a single instead of a dual 7 the car is just sitting in the garage. What I would like to try is a master such as one used in a British car that is mounted completely vertical. Have not been able to find one in the US that the brake places will say can work that way.

Factory AC in my car makes anything modern in the engine compt problematic so an under floor install would be perfect. TL, dual exhaust and shallow frame rails make that problematic too. Almost makes a hydro-boost system under the floor worth considering but that is expensive and length is an issue. The Electric high power boost system from ABS has been used in 55-6 models but IMO, it needs a higher pedal ratio for safety rather than turning up the boost and using the original 1:1 ratio which was done in those conversions.

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Thank you!

This is all very elaborate with a lot of custom fabrication and not clear if it will fit in a 1951-54 or -56 frame. I guess if one used dual 6" diameter boosters instead of the 7" boosters that were used here that might give more room.

The problem of course, with a TreadleVac car, is the pedal ratio is 1:1 and very difficult to get around that. Perhaps if one installed manual brake pedals and went this route. Far, far from a bolt-in however, as far as I can tell.

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I believe the closest to bolt in that has been found is the Electric system from ABS. It has been installed in the original space but as mentioned, those that have done it turned the boost up high and kept the 1:1 ratio. Since their master is also a 1" piston and most mfgs using that size want at least 3 or 4:1 ratio the 1:1 to me is just not safe if the power unit failed and accumulator reserve was used up.

Aside from making a bracket, one install reported no issues in the stock location but another said he had to work with shift linkage for added clearance.

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I fabricated the stepped link between the brake lever and the booster. It works but would look better if I just joggled the pushrod. (Fabricating a new engine mount would allow moving the booster up so a straight rod would work fine, also.)

I used to drive a Citroen. The DS had a power brake system that relied on hydraulic pressure (engine driven hydraulic pump) for stopping. They had an accumulator capacity to allow for 10 panic braking stops from 60 MPH with no pressure from the engine driven pump. It was safe...but I still had doubts.

Your offset in the pushrod appears to be about two inches.

Normal braking pressure with discs can run over 800 psi. Without the benefit of boost and with a 1" diameter piston that will require a 628 pound push, for example if the engine stalled or some other goofy thing occurred.

628 lbs linear force applied to the pushrod and working through that 2" offset creates a 105 lb-ft bending moment in the pushrod. Hmmmm. So I welded a nut to an old brake pushrod and applied 120 lb-ft of torque.

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I just shortened the joggle to 1" offset. Should be o.k. now for a panic no-boost stop!!! Thanks for the demonstration.
Mike

Does anyone have the details that Craig Hendrickson previously mentioned for his 4 wheel disk brake conversion? His posted website links do not work. I’m new to Packards and new to this forum.

When Craig passed his Panther website stayed online for a few months before going dark. I doubt if anyone tried to save everything that was on the site but the internet archive did collect some of the information. Here is a bit on the parts he used for the brake conversion but as has been found on other archived sites, the web crawlers apparently do not drill down to save all the sublinks and photos so those appear to be missing.

If I remember right, the front spindles had to be milled down and they were done by someone in Long Beach, California who last time I checked(10+ years ago), was not interested in doing another set.

His whole setup was a one-off custom job. Not much was off the shelf.

A suitable master cylinder and placement is more of a challenge.