Owen, I am a bit confused. Since a vacuum is an absence of air how does vacuum enter the booster from the storage tank? Do you mean the air in the booster is drawn into the vacant space of the vacuum storage tank ?

The actuation of the TreadleVac vacuum system follows the pattern of the earlier Bragg-Kliesrath (later bought by Bendix) system used on senior Packard Eights, Super Eights and Twelves from 1933 thru 1939, whether on the mechanical system (thru 1936) or the hydraulic system. These systems were pretty much bullet-proof as many still work today 70+ years later with little or so service required. A similar B-K system was used on many heavy duty over-the-road trucks thru the 50s and perhaps even later. In these sytems, vacuum is held in reserve in a vacuum storage tank, and when the brake pedal is actuated the vacuum enters the chamber of the booster. I believe the distinction you're thinking of is that in most modern units of later design, the vacuum reserve tank is actually part of the booster body.

According to the Appendix in Turnquist's book which most folks have found very authoritative, the 1937 Super Eight production was initiated on September 3, 1936 and production ceased on September 29, 1937. Nothing particularly unusual about this, the same basic pattern give or take a month on either end was pretty much followed for the next 4 decades.

John,

Thanks for the info. Would you happend to have a schematic or instruction sheet for "Pazon" unit. I think people would like to see how it hooks up and works.

It may help to answer question people may have about it.

Thanks,

Kev,
The ignition system from Pacific NW Region of P.I. does not use a HEI unit. It is designed and manufactured by Pazon an ignition company located in New Zealand.

As far as a failure leaving you stranded, the points and condenser are still in place and reversing a couple of wire connections would restore you to the original system and you would be on your way in less then 5 minutes.

John

G'day Sam and all, If you are new to Packards, it is a bit confusing sometimes. I have a 37 Super Eight which is definitely a 1937, but it was delivered on 24 November 1936. With some of the earlier Series in the pre-Thirties, Packard had lengthy production runs and one model could span a few years. My understanding is that from 1936 onwards, Packard released models annually. There were probably a few exceptions to this and far more knowledgeable people than me, around to explain it. Peter Toet

the T/V must operate completely different from modern boosters, as I know when you remove the check valve from a modern booster, even if it's sat from some time, you can hear the air being push into/sucked into the booster. I just assumed that the T/V would work on the same principle. If it doesn't, it's a bigger POS than I originally thought.

Thank you, Brian. You have it quite right, of course.

Although the power brakes vacuum canister assures that a reserve of vacuum is always available to the unit should the demand arise, the vacuum is not applied, in any case, beyond the input port, connecting hose, and vacuum piston, until the brakes are applied.

That means any brake fluid that has managed to leak into the vacuum cylinder section of the Treadle Vac is not subjected to a partial vacuum from the engine manifold unless brakes are applied.

Thus, the time duration for any of the leaked brake fluid to be subjected to engine vacuum is limited to the periods during which the brakes are actually applied.

Brake fluid leaked past the hydraulic piston seal into the vacuum cylinder is not likely to be sucked into the engine in any significant quantities, as far as I can determine.

Gauss

Sam,

Welcome aboard, You'll find plenty of Packard lovers here willing to share their knowledge and experience with you.

Are you able to enter your '40 in the Owner Registry together with a pic and any history, or how you came to acquire it?

Again - Welcome.

Quote:

John,

The good doctor may have already known, but we didn't. Thanks for sharing that with everybody. These little snippets of history are always interesting.