Well, Gentlemen, you have certainly convinced me that the Treadle-Vac has a potentially serious problem, far worse than any conventional single master cylinder problem such as on all of the non Treadle Vac Packards. There are undoubtably a large number of Packards on the road with Treadle ? Vacs or single cylinder master units.
Do we have a ?duty of care? to warn them?
I think not, because
1. Each Packard is equipped with an emergency cable brake on the rear brake shoes, the system should be in good operating condition.
2. Each Packard has a manual or auto gearbox in which a lower gear may be selected to assist in retardation.
3. Each Packard is equipped with an ignition switch which cuts the engine ignition.

I have had a number of complete brake failures, the most notable was in 1967 on the Sydney Harbour Bridge, in a 1939 Chev Master Deluxe, when I broke an axle which moved out and rendered me brakeless, gearless and speechless. The incident wrecked a good car and a potentially good relationship with my then girlfriend.
Notwithstanding that service records do not exist for over 50 year old vehicles, bad news travels via Service Bulletins, Jungle Telegraph and the Mechanic's grape vine. I have heard many stories about car's weaknesses but I have heard none about the treadle ?vac. I hope that mine continues to give good service in the 56. I am about to fit a remote power booster ( non treadle ?vac) to my 1938 Packard 120 and that may be another thread. Best regards and it has been a very interesting item, once again I am sorry that I unfairly involved Silicone brake fluid. Peter Toet

Jack, the spacer goes in there because the two pulleys won't bottom out together when assembled. Hence the spacer (I used a couple of washers to dial it in) to make it a solid unit. It's been in my Pat for over a year, at speeds over 90 miles an hour several times, with all the load from the supercharger on it, since I don't have the spring loaded idler like the Avanti originally had.

Straight eights are easier than the V8's, by far. All you need is an HEI unit off of a '70s Pontiac, and use the original lower shaft from the stock Packard distributor. You just drive the pin out of the Packard shaft to get the lower part off, then cut the Pontiac shaft to the appropriate length. You'll also need to turn down the lower housing on the Pontiac distributor, then have a sleeve machined to fit into the engine block of the Packard. I used the lower bushing on the discarded piece of lower Pontiac housing to connect the new sleeve to the Pontiac upper housing. The Pontiac is the best way to go, as it's already the correct rotation. If you have any questions, and I'm sure you do, feel free to ask.

"If there is a spacer between the two pulleys, then the outer portion is no longer an interference fit and thus is un-supported. Am concerned the sheet metal might eventually fatigue."

Then use a spacer of the correct thickness.
REGARDLESS, if metal fatigue would be an issue by not being supported then we really have a BIG PROBLEM with the water pump pulley. NO support there!!!!

"Cutting to the chase", has anyone documented a case where the compensator port spring has actually failed in operation? "

How much documentation exists (ever released to public or dealers) about ANYTHING failing prior to ca. 1965 ????
Witness the V8 oil pump. Relatively little documentation compared to the size of the problem as well as most of the documentation that is KNOWN to exist is questionable in relavence to the problem anyway.
It was FIFTY years ago. Not 10 years ago. It was a different world. A 30 day warranty. Not a 5 year warranty.

As for the steering head breaking on the 1907 Trump, i mean what do u want???? How much documentation exists for a 1907 ANYTHING ???? How much did they publish in 1907 anyway???? Probably very little.

One can not use 2007 expectations or analysis to explain something that is 50 to 100 years old.

Peter packard wrote:
" Risk Management is the key to survival in any vehicle, old or ".

Precisely the point of my previous post. The spring is either broken or it is not. It either works or it does not work. It's called the law of "excluded middle". Kind of like On and Off. NOT kind of broken or sort of broken or somewhat broken. If it breaks there is NO, NONE , NOT ANY brakes whatsoever. There is NO forewarning!!! There is no recourse for pumping or slamming the pedal to achieve braking affect.

This is simply NOT true of the more convenventional piston and seal type cylinders wheather dual or single. If the seal becomes deficient then it tends to happen rather slowly by wearing at the sealing edge of the seal. USUALY the conventional type will (on FiRST WARNING) fail on a lite to moderate pedal pressure. When it goes to the floor the first reaction is to release and SLAM the pedal as hard as possible to the floor. This sudden and extreme act tends to expand the seal a little more allowing for adequate braking effect. OR a pumping action of the pedal.

Again, If the TV spring fails then there is NO brakes!!! NO RECOUrSE!!! NO WARNING!!!! NO NOTHING!!

I really do not know how to explain it any more plainly nor clearly than that.

Greetings, Eric,

It is to be hoped your simple solution is permanent. Question. If there is a spacer between the two pulleys, then the outer portion is no longer an interference fit and thus is un-supported. Am concerned the sheet metal might eventually fatigue.

Second point, even though the harmonic balancers you mention have the same bore diameter as the Packard, none of them are cantilevered way out as is the bad-science Packard design. I am using a Ford Racing balancer on my hot rod engine. If you want to try one, I have an extra. It does require using a different water pump and grinding off the timing tab from the front cover.

thnx, jv.

Your logic is correct. This is a common failure with the switch--particularly if it's been around silicone fluid. NOS available but pricy. There's a VW replacement some have had luck with (113945515G) that has different terminals--blade vs the round bullet type--so if you have blades, perhaps someone has already switched.

Another option is to convert to full mechanical operated by brake pedal. The picture shows one method of mounting and the parts I used. Mr. Berger sourced the Standard aftermarket switch at his local parts store.

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Dave,

Thanks for the offer, but the 51-54 Manual is already online here. So no sense it going through that marathon of scanning. But I do appreciate the offer.

Try Kanters, or Tucson Packard. I belive they had a stock of correct jacks last time I checked. They wanted something like $100 for them.