Packard Forum Index » Modification Discussion

Alrighty ill be sure to review the service manual.

The manual should also help me with some other things about the car for the future and such especially sense i don't exactly know what I'm doing so I'm definitely learning as I go, probably doesn't help that I'm probably the youngest parkard owner on record right now but I think it will be fine

And yes i know of the issue with old brake fluid that was the death of the old original master cylinder that I had found in the trunk of the car when I bought, thing was just completely dust on the inside, but don't worry the brake system has already been flushed of all the old brake fluid and has been replaced with new stuff already that was done when the brake line were fully replaced.

Your vacuum hose is quite OK where it is for the time being as it will supply full manifold vacuum for the booster. Just trace the hose and make sure it makes it down to the port on the side of the canister attached to the master cylinder. Looking at your engine compartment shot, I am bamboozled by the large silver apparatus hanging on the firewall. It looks way too large to be a fuel pump and I am wondering if your brake vacuum hose is attached to or passes through it. If so, there's your trouble. As mentioned, you need to have full manifold vacuum supplied to your brake booster.

That extra nipple that sticks out the back of your carburetor is probably supposed to go to a PCV valve for crankcase ventilation. For now just plug it and it will probably make your engine run much better.

The reason the original engine had a check valve in the vacuum system was to hold vacuum for a time in the booster system in case the engine stalled in traffic. That would insure a couple of power-brake applications so you didn't careen into the back of the car in front of you. I doubt if half of the cars that come through here have one that works.

On back of the carb.

Looks like an air chuck fitting.

For Ross

Ok well that is good to know that where the hose is hooked right now is fine so that is definitely a relief

As for what your looking at on the fire wall, yes that is a fuel pump and it works nicely and no i know for a fact that the vacuum hose is not hooked to it or running through it the fuel line and the vacuum hose are completely separate from each other

For reference, here is a figure from the installation instructions for a Holley intake manual which shows the brake vacuum connection location:



The Packard Service Manual provides a very good description of the operation of the Power brake unit in Section 4 starting on page 5.
Service Manual Section 4 Brakes

You said of your Chevy 350 "it has a Holly intake manifold and an edelbrock carb on it.", do you know what cam is in it?
If the carb and manifold were changed, they may have also changed the cam which could significantly reduce the vacuum output.
Hooking up a vacuum gauge will show how much vacuum is available to the power brake unit. This would be good information to have in moving forward with this diagnosis.

In your initial post, you said "after driving the car around for a bit I noticed that that car would take a decent bit to stop at any kinda real speed and that is also wouldn't come to a full stop but still continue to roll slightly after for the most part stopping". Did you mean that the braking distance increased over time or that you didn't measure the condition until later in your test drive?

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I don't know what your brake cylinder inspection process is.
Packard's brake cylinder inspection on page 4 of Section 4 of the Service Manual includes removal and disassembly.

Brake cylinders are relatively inexpensive and readily available.

Ross has a good video on adjusting drum brakes.

Well it is good to see that you managed to find the exact Holly intake manifold that my motor has and also vary good to see that the vacuum hose is hooked up to the right area.

And as for what the cam is in the engine i don't know exactly what it currently but I will hopefully soon know what it is when I remove the oil pan cause I'm needed to replace the oil pan gasket anyways so I'll have time to look and find out

I don't have a vacuum gauge currently so sadly I won't be able to measure the output to the power brake till I can get one.

And no in my initial post I had only stated what was going on the braking distance didn't seem to change nor did i preform a test to measure the braking distance to begin with.

But I have just decided to just replace all of the brake cylinders regardless of what there condition is just to play it safe.

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I don't know if you will be able to see anything with the oil pan off, the cam is behind a lot of stuff and I don't know where it would be marked.

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You can't work on a car with flint knives and bearskins (to paraphrase Mr Spock) so buy the tools you need for the job or take it to a shop with those tools. A vacuum gauge is very inexpensive so would be a good place to start and the better ones are handy for all sorts of things.

As for the cam, it will be pretty much hidden above the crank so you likely won't see much from underneath.