Re: Brake lights stay on

Posted by HH56 On 2017/2/24 21:14:19

What O_D said. If the Stude master is similar to those Packard used the internal port referred to is almost directly under the fill cap. The brake free play must allow the piston to move back past them so they are open. Packard cylinders had two of the ports -- one in the rear which is fairly large and and one in front of that which looks large but is actually a chamfer and only has a very tiny hole thru the middle. That port was prone to rust or debris filling the depression and blocking the tiny hole. You might check out yours and see if it has a tiny orifice that is blocked.

Believe the hill holder was an option so no way of knowing if the car was equipped without seeing the car or the build slip. You should be able to visually locate it yourself. If present, it is a roundish cylinder with a lever on the side and brake lines connected to one end. It is mounted on the inside of the frame rail directly opposite the master cylinder. The master is mounted on the outside of the rail. The lever on the side will have a rod connecting to the clutch pedal and linkage.

If the unit is working properly it should not come into action unless the car is on an incline with the rear down about 5 or so degrees and the clutch is depressed. As the clutch is released, the rod should move the lever which pulls the mechanism that provides the fluid block away from the brake lines so fluid can return to the master and free the brakes.

If your car has the Hydrovac power brake booster a problem there adds another layer which could add to the puzzle but not sure if hill holders were used with those.