Packard Forum Index » Modification Discussion

The Dual mc was promoted as "added safety" in and about the time that (US) disk brakes became popular. THAT WAS ONLY A PROMOTION GIMMICK. I'm not sure about the technical dynamics of the disk(front) and drum (rear) offering of the late 60's but that was the REAL reason why the dual MC was introduced. BECAUSE OF A SPLIT DISK/DRUM ISSUE.

NOT JUST BECAUSE IT IS "SAFER".


SINGLE v DUAL MC controversy is NOT related to the issues regarding the BTV failures.

At some point someone, somewhere, will have to take the bull by the horns and resolve the TECHNICAL controvery surrrounding the BTV issue one way or the other. I just hope someone ELSE will.

Owen_Dyneto said:
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I can guarantee you that my 55 Pat was neither poorly nor non-maintained! The BTVs that failed were professionally rebuilt (not by me) at significant expense by the best commercial restoration businesses that I could find.
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Airplane accidents do not happen very often either, but when they do, they tend to be fatal to the occupant(s).
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<p>Rather than argue about how many angels can dance on the head of a pin, I have provided the examples and a solution. I you do not think a BTV failure will ever happen to <b>YOU</b> just because it <i>never has</i>, then go ahead and continue whistling by the graveyard.
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Craig

"The BTVs that failed were professionally rebuilt (not by me) at significant expense by the best commercial restoration businesses that I could find."

Ok MR Engineer, raceing engine builder, Ponticac expert and Air Force Commander. Did u disassemble the BTV to analyze WHY it failed????

To get around the leverage problem how about installing a non power brake pedal assembly with a modern power brake booster/cylinder?

I'd also like to know why none of the high dollar, professional, experienced BTV rebuilders approved by the Packard Gods are not chimeing in on this for over 10 years gone by.

OH! OH! Yes i forgot, They are much too busy with their bussinesses to address this issue. I mean Jesus Christ!!

WHat is all of this turning into anyway???? Somekind of a Country Club???

I'd also like to know why none of the high dollar, professional, experienced BTV rebuilders approved by the Packard Gods are not chimeing in on this

Not sure what you mean by the Packard Gods, but vendors and providers of services are free to advertise in PAC publications, but to my knowledge PAC does not make any recommendations as to one source or vendor or another.

I did speak with Ed Strain yesterday, he was more than willing to take 1/2 hour and discuss thoroughly his experience with the BTV and other power brake boosters. If you want communication with a rebuilder who knows these units better than any of us, pick up the phone.

Anyway, I'm tiring of this subject as I'm sure some of the rest of you are. Time to move on....

PackardV8:
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Keith, good question. Short answer: At the time I was gainfully employed, working 10-12 hours a day with a new girl friend and her family. Since I had much more $$ than time and the BTV was a "black box" to me, I threw money at the problem.</p>
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Later, after 3 failures, I figured that approach was not working and a 50 year old "black box" was somehow deficient in design so I spent my engineering expertise on figuring out a <b>NEW, MODERN</b> way to fix the problem. I still do not know or care much about the BTV internals or failure mode(s).
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<p>I do know that in the seven years since installing the MPB and relocated pedal solution, I have not had the slightest hint of a brake problem despite driving my 55 Pat extensively.
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Sometimes, it is just better to move on.
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Craig

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Calm down, OK? The message I intended in my post was that the T/V is probably no more prone to sudden catastrophic failure than any other single MC system. As I see it, if you're going to modify or fix a T/V, you don't gain much, (if anything) safety-wise, unless you convert to a dual braking system.

The advantage of a dual braking system is that you basically have a backup in case of loss of pressure in the system, for whatever reason--not necessarily the T/V or other single system. You have 0 brakes. Wouldn't it be helpful to have 50% brakes rather than none? And wouldn't it be nice to know before you have to stop that you possibly only have half your brakes?

There are many layers of system backup there are in commercial airliners. It is all a matter of improving the odds, and the odds of a plane crash are very low.

As for the warning light, it makes sense to have one, just like you wouldn't drive around without a working oil warning light or gauge. And you'd stop the car if you saw the oil light on wouldn't you? So, isn't a brake light warning just as essential? I mean, would you rather have something that makes it go fail and give you a warning rather than something that makes it stop? But that's a personal decision.

Having been in a car when the T/V failed at highway speeds, I know how long it takes to stop using the emergency brake. Unless you have lots of clear road ahead, you're toast.

Would I replace a T/V rather than upgrade? I don't know. I tend to put things off.

I'm sorry if my posts aren't helpful, but they are on topic.
As I read it the topic of this thread is the pros and cons of changing out a T/V system for added safety and reliability, not a discussion about how best to fix one. There are helpful hints on that elsewhere.

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I agree that the dual braking system adds a measure of security but are not fail proof either. If the M/C piston fails then there are NO brakes either and I have had that happen on my Mercedes 450SL just after bleeding the brake lines (fortunately in my driveway and not on the highway).