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Hey yall just a few weeks ago I got my 55 packard clipper custom touring sedan back from the shop after having its brake lines completely replaced so I have already went through and bled all of the lines and did all that but now after doing so the brake pedal is now completely rock solid to the point you can't almost compress the pedal really. But even with it being so solid the brakes work nicely and are sensitive because of it so I don't know if that's just how it's supposed to be or what

But yes i have already driven the car around and confirmed that yes the brakes do in fact work now (thank God lol) but I did notice that one the brake pedal is rock hard as I stated and that 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.

So I'm not sure if I just need to adjust the brake shoes a bit or if it's also just because of the small build up of rust on the pads and inside of the drums (and yes it has all original drum brakes) or what and just simply if the pedal is supposed to be so solid to the point you almost cant compress it

Also would love even more advice when coming to working on my 55 packard clipper and to have individuals to specifically talk to about specific aspects of working on the car

Thanks.
Thomas.K.

Do you have power or manual brakes? I would assume power on a 55 Custom.

I suspect the vacuum assist is not working properly. The power brakes do not have that much travel, but are VERY sensitive compared to modern power brakes. However if the power mechanism is not working, they will feel hard and ineffective.

Is the vacuum hose even connected?

Yes it does have power brakes, and i do remember hooking up the vacuum hose to the booster when reinstalling the master before it went in to be worked on and have all new brake lines added but I might have come off or the hose might even be bad so that is definitely something I will check this weekend once it gets nice again here

Also check the one way valve at the manifold and the vacuum storage tank behind the left inner fender.

Good point. If you unscrew the check valve at the back of the carb, you should be able to blow through it from the hose side over to the carb side.

You say " the brakes do in fact work now (thank God lol)", you were "reinstalling the master", and you have had "its brake lines completely replaced", what else have you done to the brake system, if anything?

If the drums have rust, did you inspect them as a part of this work?
Did you replace the brake shoes? If so, did you check how they contact the original drums?
Was the master new or rebuilt?
Did you rebuild the Treadlevac unit?
Did you replace the brake hoses?
Did you replace the wheel cylinders?
Did you replace the vacuum hoses and source?
Have you checked for vacuum leaks? Is the pedal as hard to press when the car is running as when it has been sitting a day unused?
If the "car would take a decent bit to stop at any kinda real speed", does it stop in a straight line or pull to one side?

If the car "wouldn't come to a full stop but still continue to roll slightly", there is some contact between the shoes and drums, but not enough contact, travel, or pressure to stop.

Make sure that the shop that worked on it arc-ground the new shoes to the measured ID of the drum. This is a vital step that a lot of shops don't know to do today.

Quote:

Finding a place that has the equipment or will even arc the shoes today may be hard so you could do the quick and dirty trick of spreading the shoe to match the drum as Ross shows toward the bottom of this post. There are a couple of other tips given after that post that may help the brake lining make better contact too.

As someone else mentioned, the Bendix Treadlevac system Packard used is very sensitive and has minimal pedal travel when compared to other power brake systems of the day and particularly when compared to the modern type power units and bolted on masters. Those made and typically used on cars in the last 50 years are considered modern systems. The one piece integrated Treadlevac master/power unit was an early development of the postwar era when car power brake availability was being introduced and designs perfected. Its operation is quite different from other units. Treadlevac uses a comparatively large diameter rod which does not touch the inside of the master cylinder other than where it enters thru a seal at the end. The rod or ram is forced by the pedal into the closed space filled with fluid and displaces the fluid to send it to the wheels while other systems of the day and all modern units push a volume of fluid sitting in front of a piston out to the wheels. Even though the typical automotive piston setups require a higher mechanical pedal ratio to get the equivalent force as the ram and a longer travel to accomplish the same volume of fluid delivery they had other advantages and ultimately prevailed.

There is a YouTube video of a Packard commercial with a 53 or 54 Patrician. The dainty woman driver lifts the tip of her shoe off the gas and rotates it over to barely touch the brake to bring the car to a smooth stop. I know for a fact that pushing down hard and getting the approx 3/4 to 1 inch maximum pedal travel in a properly adjusted and working Treadlevac system will try to put you thru the windshield.

Thomas, what HH56 said is really the gist of it. Anyone familiar with these cars can tell you that these units have so little travel that with the power assist, they often feel too sensitive. Strictly speaking, they can only feel rock hard if your vacuum assist is not working. But if you can push it down the distance (you will also hear a faint "woosh" sound), and your brakes still don't work well, then it's the typical questions like 56Clippers sent.

I checked it and the hose does have a small kink in the line that might be cause issues with restricted pressure flow so I'll try and fix that