Packard Forum Index » Modification Discussion

After doing some searching here I see that there are strong opinions about the Bendix treadlevac both pro and con. In the event that the unit on my 53 Patrician is toast is there a viable alternative?
Thanks

You & Brandon & others ask the same question. I haven't changed a unit to anything else but Turbopackman and Craig and maybe PackardV8 have. Hope one of them sees this thread and gives their experience and opinion as to the alternatives.

Craig has one version he did on his sitehttp://www.1956packardpanther.com/ (look under special projects) but don't know if he has done any more to it. There is a different approach also under Paul's Executive.

I'm fairly sure because of the location and space constraints there is nothing that just drops in the original space and works without limitations.

I wonder if this is the next question to ask some of the Brake Conversion vendors. Most of them sell a variety of different MCs and booster and pedal configurations. I'm sure if they can come up with a disc brake setup that works, then that could come up with a MC configuration that would bolt in.


On the Non-Power side, I think I may have a solution to convert the front frame-mounted single MC to a dual MC that is used on the 51-54s. I believe the '55s have it mounted under the floor if I am correct. Stay tuned.

I was motivated to change out the Bendix Treadle-Vac (BTV) after 3 failures on 3 different units. One failure was complete (no brakes) at 20mph and the other two were leakers stopped in traffic. After conversing with six other Packard owners about failures with their BTV, that was enough for me.

The Master Power Brake dual master 7" unit documented on my 1956PackardPanther.com website has been superseded by another number, but I am told it is essentially the same. It does fit in the same location as the BTV with very little modification. The remote fill is optional, but well worth it.

HOWEVER, the MPB unit requires a 3:1 pedal ratio to generate enough line pressure to actuate the brakes. The BTV pedal has 1:1 (direct) and this does NOT work. I came up with a way to remount a 1956 pedal assembly to create the requisite 3:1 ratio. It is not pretty and it relocates the pedal itself lower toward the floor, but it has proven to be completely reliable over these many years. It is just a matter of retraining your muscle memory to the new pedal position.

Craig

There was a discussion over on "unidentified engine noise" that mutated into a TreadleVac discussion, so I'll copy my experiences and comments over to this thread.

Though I don't understand the comment that you can't even check the fluid level (unit must have been installed with the cover reversed!), TreadleVacs have certainly become contentious units. They were used as original equipment in millions, perhaps even tens of millions of cars between 1952 and about 1962, I believe Lincoln was the last to use them about 1962 though Mercury, Cadillac, Chevrolet, Packard and many others used them apparently without consequence in their day. GM then developed their own version, manufactured by Delco-Morraine, generally thought by many to be a somewhat inferior unit. I've owned several cars with the Bendix unit and never had an issue, thru many tens of thousands of miles, as have many others. Yet there are stories to the contrary which I don't doubt, attributable perhaps to poorly done rebuild jobs or neglect. There are some key parts which are not included in rebuild kits and are only available from the better of the rebuilders like Ed Strain who have them made for their own captive service operations. Given the importance of brakes, I don't see that $210 or so for a top-notch rebuild is a problem.

Quote:
<p>About 7 years ago, I paid $450 with core charge for a rebuild from Whitepost Restorations, a reputable firm. That was one of the units that also failed.</p>

<p>Pick your poison and take your chances.</p>
<p>Craig</p>

The fact that it's a single line master cylinder to all four brakes is the most dangerous part of it all, let alone the fact that the brake fluid mysteriously disappears causing total brake failure.

They need to be destroyed, period.

Vlad the Impaler! What a metaphore! Well done, Eric.

Craig

Like I said, put the f'r out on the front lawn on a stake, I'm half tempted to do that with the one I have laying around, but no-one would get the joke but you and I.

While you guys may be right, it would be nice to come up with an alternative that wouldn't require major surgery before staking them all in the yard.

Since it presently seems major surgery is all that's available, then some photos & component x-refs that have been successful and look like something Packard might have done would be a help for anyone contemplating a stake in their own yard.

Didn't some mfg use a bellcrank and mount their master cylinder at 90 degrees to firewall. Wonder if that would be a possibility to raise high enough for the proper mechanical advantage for the unit Craig found & still be under steering column.