'69, stock Power Front Disks, rear drum. Booster and Master Cylinder were swapped before paint/body/engine work. All worked fine before we took it down, even though I did change rear brake lines and cylinders on rear axle. Nothing was undone or dismantled as it relates to brake system after last drive. It has been almost 12 months since it was last driven.

Today was first "road test". All was fine, but brakes don't seem to have "boost" on it. Car stops, but I just thought it had more "stop" to it before I started the work.

I pulled check valve a bit and got a definite whoosh sound, so I have to believe I'm getting plenty of vacuum at the booster. I'm going to bleed rears (and fronts as well I suppose) again, but does anyone have any more suggestions on trying to make sure the booster is doing job? I also saw the post that said to pump up brakes and then start car with foot on brake pedal to see if it drops, which I can try this week.

Thanks for any suggestions.

It might also be a good idea to bleed out all the old brake fluid.

I do believe DOT 3/4 is hydroscopic (meaning: it absorbs water). It may not be a fix to your problem, but with your car sitting that long its a good idea to do it.

How much vacuum are you pulling?

Joe

Unfortunately don't have a clue on "how much vacuum". Sorry.

I did do the pump up/start up thing and the brake pedal did drop.

I'll try to bleed them this week to see if it makes a difference, and if that doesn't work, I'll try the change in the fluid as well. Perhaps the bubbles finally settled out in the rear line change over the sit time and now has them in need of rebleed.

Thanks for responding.