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"Using the cam manufacturer's break-in lube does NOT solve this problem. As I understand the situation, the problem is the lack of zinc in today's oils."

Well yes and no.

Wiping a lobe during the first 20 min 2500 rpm break in period (or very shortly after) after a rebuild, that's usually due to not using the correct or any cam assembly lube. Motor oil isn't good enough, you need to use the right stuff. Fred's right there, that stops returning cams 30 days after they were bought. Many manufacturers want you to remove the inner valve spring during the 20 min break in now too. I didn't, i admit it, but my springs were almost stock and the cam was pretty mild.



However, for long term protection, you should continue to use the zinc based oils or an additive so you don't wipe a lobe down the line.

So both are wiped lobes, but you need to do both steps as cheap insurance against failure eventually.

Brad Penn makes excellent oil, and i run comp cams 10-30 motor break in oil in my 71/428 as a regular use oil. It's 4.95 a quart at summit (about an hour from me). I found a guy 3 miles away that carries brad penn so i might migrate to that. I think valvoline VR1 has the zinc in it also? The race oil variant of valvoline maybe? whatever it is.

There are also 100 additives that do the same, but if you can buy it already in there, why pay $12 more for the additive.

Bozonono.

Can give us somemore detail:
1. Does the rear brakes seem to grab more than the front???
2. Does the car nose dive???
3. haveu u tried adjusting brake shoes according to manual???
4. Try disconnecting or adjusting PARKing break.
5. how far does pedal travel????

valvoline.com/products/consumer-products/motor-oil/racing-motor-oil/6

It states VR1 is not a synthetic oil.

"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." What does that mean silicone sealer in the return channel? I have one TV unit rebuilt wherein after awhile the brake pedal no longer returns and I have to pull it up with my foot after each application, but the brakes work fine albeit on all four of my Packards with T/Vs I must refill the reservior often, presuming the brake fluid is getting sucked up into thje carburetor because with four cars I figure I'd be able to find a leak if that was the case.

What does that mean silicone sealer in the return channel?

There is a port in the casting between the reservoir and the space between hydraulic seal and vacuum seal. Its purpose is to let fluid go back to reservoir if hydraulic side leaks and if vacuum side leaks, allows it to suck air from vented reservoir. If blocked, there is nothing preventing a leaking vacuum seal sucking fluid or if hydraulic leaks, forcing the fluid into vacuum side. On yours that needs refilling, I wouldn't be surprised if you took it out and opened it up that you would find the vacuum side with fluid in it.

There are a number of gaskets in units possibly even from factory and in some rebuild kits which have that port covered or blocked because it appears the gaskets were designed for a different cover than Packard used so the same problem.

There is only the one big spring inside vacuum side pushing against the vacuum piston to return the pedal. If nothing is binding on the carpet or pedal side, then possibly the vacuum piston has been greased with improper lube and that is sticking or the spring has broken or become weak. If the leaking unit is the same one that sticks, perhaps it has got brake fluid in it and that is gumming up the leather seal on the power piston.

Here is a picture of the reservoir showing the port. This one has it open to reservoir, on later models with the gasket problem, the port opening is solid all the way to bottom of lid where gasket seals it.

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Because of the physical location of the vacuum line, it is a very remote possibility that the brake fluid is being sucked into the carb. Most likely it is being drawn into the vacuum canister. That is fairly easy to check - roll back the rug, remove the toeboard, and remove the lid of the vacuum canister. Remove the screw for the air filter and the two screws for the rubber vacuum line. Remove the connector for the internal hose. Pull out the vacuum piston and see how much fluid you have in the canister.
Come back and let us know what you find.

Someone said that perhaps the reason that I can;t get failed units to examine is that many have been replaced with modern units. I haven;'t been keeping track of the names of the posters but I am guesing there have been 5 or 6 people who have posted on this site who have done so.

Anybody keeping count?

Hi just wondered how your project went and how much $$$$ and aggravation it caused you?

The brake unit on the 1953 Buick Skylark was a Kelsey-Hayes design . . . not Bendix and not Moraine. That's the one that had the problems described in the Nader book.

Well, I'm guilty of stating - and in more than one thread/post, here - that Moraine was the culprit, but thanks for correcting us that it was Kelsey-Hayes.

I've not read Nader's book, but only an excerpt that was available online. It provided a partial transcript from a relevant court case, and went on to cite a dealer bulletin. However, it did not identify the power brake unit supplier, but focused on negligence on the part of Buick/GM.

I can't recall, now, where I specifically got that mis-information on Moraine.

Still, the main point is that the villain was NOT the BTV.