Packard Forum Index » General

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Agreed on the last point, Fred. But even though the rest of this is a bit OT I'll risk it, since you brought it up on your own thread! In short, disc brakes do have that same problem when wet. Any brakes submerged in driving through deep water will have some slippage after you re-emerge (if you need to stop anytime soon thereafter). I have noted this MORE with disks than when I used to drive lots of front drums. Reason being, I suspect, is that disc rotors are wide open to the water, and if the puddle is deep enough, the pads get submerged, too. You have to get into a puddle that covers the whole wheel to effect both shoes on a drum setup.

A good preventative measure is to apply the brakes gently while going through deep water, which will wipe off most of the water that would otherwise adhere to the braking surface, and also keep the pads/shoes dryer. For long stretches in the soup, it's best to use the brake and accelerator simultaneously, balancing the "go" with the "slow". This little tip is not of my own invention, but I have tried it and it works well.

With drums, in general, finned ones are great for dissipating heat more quickly. I had an Electra with the "Al-Fin" aluminum alloy finned drums, and they were very good brakes.

However, I'm not sure aluminum, with its higher rate of expansion, is such a good idea. One reason for drum brake fade that is not often mentioned is that the braking surface actually RECEDES from the shoes as the drums heat up. The less expansion of the metal the less resulting fade. Conversely, with discs the rotors expand with the heat and actually give MORE braking pressure--an advantage of disces not often noted.

Finally, considering the earlier comments about long downhill runs with a lot of weight in the car, HAVE YOU SHIFTED TO A LOWER GEAR?? Mountain truckers have gotten along with (admittedly huge) drum brakes for a long time using this simple precaution (and admittedly sometimes needing to use water cooling).

But using the common sense of selecting a lower gear for the downgrade is almost always sufficient for any passenger car with drum brakes (and the same precaution should be taken with discs as well).

Put 'er in "L"!

As far as the 'on-topic' portion of the message, I have no doubt I'd be quite satisfied using an original Treadle-Vac braking system on any Packard, as long as it was thoroughly checked out for pitting or bad seals, and I had a solid, well-lubricated e-brake, and plenty of practice using it--which is a good idea no matter how modern and "foolproof" the braking system on a car might be.

I am calling again for reports form Packard drivers who have had BTV units fail when driving. I would like to inspect these units to determine the reason for failure.

Thus far I have received only one such unit which had recently been rebuilt by Ed Strain of Fla, a known rebuilder. He filled in the return channel for fluid with silicone sealer and it was just a matter of time before it was depleted of all fluid and the brakes failed.

This is not a design or performance failure of a BTV, it was that the rebuilder did not understand how the unit functioned and he thought he know better.

Maybe everyone who had at least one BTV catastrophic failure threw theirs away when they replaced it with a modern dual power unit. That's what I did. If so, that explains why no one has come forth to your request.

As to whether the failure should be attributed to a design or rebuild flaw: it hardly matters at the instant when one has NO BRAKES. A new modern unit has no such possibilities.

Now that HH56 has designed a levered pedal arrangement which keeps the pedal pad in essentially the stock position and looks stock from the interior, there are no more excuses for keeping the "failure-prone" 55-yo BTV.

JMO,

Craig

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" ..filled in the return channel for fluid with silicone sealer and it was just a matter of time before it was depleted of all fluid ..."

Where did the fluid go???? I'm guessing it was sucked into the power cannister????

To Craig,

In my opinion the BTV has gotten a bad reputation due to poor workmanship in rebuilding. IN the 50's 60's there were tens of millions of BTV equipped cars on the road and not a rash of accidents/failures.

If there were a number of rebuilders of flat tappet (vs. modern roller tappet) engines and some recently rebuilt collector car motors self destructed within 1000 miles would you propose all flat tappet engines be replaced by late model Chevy 350's ro Ford Modular engines. There would be no more cam and eventualy entire engines?? Or would it be more reasonable and prudent to instruct rebuilders to coat the cam with break-in lube?

In fact this has happened already. We sell 1000's of new and rebuilt cams a year and in the past 10 or so years experienced warranty claims saying a few lobes were soft as they were destroyed.
If you know about hardening it is like saying 3 slices of a loaf of bread were not baked...impossible. The problem is that the rebuilders were not coating the cams. Since that we have included cam prelube and instructions with every cam. Now we have perhaps one claim a year, we have educated the rebuilder.

We've sold over 15,000 BTV kits over the past 40 years with very very few comments that the unit failed. We include Bendix prepared instructions that of course to not say to block the return channel with silicone.

Any system, brakes, carb, oiling, air cond, electrical etc will have disasterous results if fixed in a haphazard or incorrect manner. That is not a call to throw out original and modify.

If someone fillled your modified system with motor oil or trans fluid adn you lost brakes in 100 miles wouild you modify it again or find the cause??

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"In my opinion the BTV has gotten a bad reputation due to poor workmanship in rebuilding. "

Yes. Ok. But SPECIFICALLY who are the qualified rebuilders of BTV's ??????

For over 13 years now and across 3 different web sites one of the recently named BTV rebuilders was often touted as "qualified" or "highly recommended for years". Now we find out he's not????

So specifically who are the qualified rebuilders of BTV's???

Today I contacted ABS brakes in Orange California, ph-714-771-6549 ask for Tito, to inquire about a dual master cylinder power brake system to replace the Treadle Vac system in our 55 Constellation. Was informed they manufacture an electric dual master cylinder power brake system with custom brackets that replaces the Treadle Vac system with no changes to the pedal. The system apparently fits in the space of the original in the engine compartment. In about two weeks I plan to order the kit and install. Will keep everyone informed of the results.
I do not want to enter the debate of the Treadle Vac system just think it is safer to have a dual master cylinder setup. When we restore/rebuild a vintage car safety issues addressed include adding radial tires and a dual master cylinder. Nothing wrong with original equipment just my preference.
John Miller

To John Miller:
No disagreement that a dual M/C is safer than a single as long as the pedal position is not compromised so it is difficult to use or reaction time is increased. Interested to hear how it works out.

John Miller writes:

" Will keep everyone informed of the results."

Yes, please do. Thanks.

I think there have been at least two Electro-boosts installed by posters here. Mat in Australia on his 55 and I think another was possibly Jed on the East coast.. Don't know if Mat has driven his yet as there was more work being done to his car after his accident when BTV failed and don't remember seeing any feedback on any others. I think one also changed the pedals with the conversion so not really the Packard setup there. Downside to the Electro-boost is the price is $1000 or so and not strictly a bolt in either. Upside is it's output is adjustable so you may get away with the 1:1 and can also adjust for the feel you like.