Ok another question I need answered in order to get this classic on the road. I just work on the break. All of them are bled and there does not seem to be air in the lines. I just added the self adjusters to the back breaks which the last people that worked on it left out. Any way it has basically new breaks all around. However, the breaks are hard until i turn on the key and when the cars running the breaks go way down. Is this how they are supposed to be or is there a problem?
If the brake pedal goes down low after you start, you may have a torn diaphragm inside of the booster. All the vacuum lines ok? Can you hear the booster hiss when you hit the brake while the vehicle is running?
How low is low? They pedal is supposed to drop some when the booster has vacuum! ;-)
To see if the rear shoes are adjusted properly pull up on the hand brake and see if the pedal continues to drop the same amount. It should be a little higher but not a lot higher. ;-)
Does the fluid level go down any if you press and hold the brakes down multiple times? If so, you have a leak somewhere. It may be a bad caliper at one of the wheels, but a car of that age could have rusted brake lines too. I recently had a similar problem, and couldn't figure out where it was leaking. After tracing the brake lines, I discovered the brake lines in my
1976 Rabbit run through the passenger compartment and had rusted through under the carpet. So I had to replace the brake lines and clean up a mess of brake fluid in the floorpan. :)
If you press than hold the brake pedal down, does it slowly drop to the floor over time? If so, you could have a bad master cylinder. Basically, the seals in the cylinder are letting fluid leak by, and the pedal drops accordingly.
But, you description seems to indicate the brakes are fine until you start the engine. Which leads me to think that's just the normal operation of the vaccuum brake booster.
You might check the freeplay on the brake pedal, but if the brakes work well, and you aren't losing any brake fluid, I don't think there's any problem.
There is not leaking anywhere. It seems prior to my purchase of the car the breaks had recently been redone as all the lines and everything are quite rust free.
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