Packard Forum Index » V-8 (1955-56)

I need help with my packard brakes.
brakes are redone last year and they worked perfectly.

Now the brakes are jammed. pedal is hard and you can not press it. all 4 brakes are locked but when you release the pressure away from lines, car rolls like it shoud be.

clearly, mastercylinder wont let hydraulic pressure back to fluid tank.

I Disassemble the master cylinder for service but I don't find anything wrong with it.

can anybody notice something that i dont?

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Remove your finger.

The shaft should move when you cock it.

the shaft moves..

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Two scenarios: The first is that something in the vacuum section has failed and and the power piston is being held down by engine vacuum. In that case the brakes would release not too dreadfully long after turning the engine off.

The second is much more likely: The power piston and consequently the hydraulic piston are not moving back far enough when you remove your foot. The hydraulic piston must come back far enough to tip the compensator valve open. This can be caused by a weak spring, hose clamps on the vac hose, or in one case I saw, the felt silencer pad had been installed inside the booster rather than in the boot.

*Broblem solved*

Valve in first three pictures was incorrectly installed.

I turned it around and now the brakes are working like they should be.

Just for completeness, do you have a picture of how you turned it around?

I turned spring/seal/metalpart set other way around.

This picture shows correct assembly.

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Question I understand that you said it work before then quit how could that be if valve was assembled wrong before. Just asking unless I misunderstand that it was not working before

We dont get answer for that question ever.