Help troubleshooting brakes on 55' w/power assist

[240z4u]

This is my first post here! I am a car guy by nature and my dad has a 55' bird. He hates driving it (he just got it last year) because the brakes are so hard and the steering so vague.

I got the steering worked out.

As for the brakes with power assist. The power assist is definitely not working. I took it out and drove it without a vac. source hooked to the booster and it brakes exactly the same as it did with it.

I applied vac. by using a vaccum pump to the servo and it holds vac. fine. The check valve is defective though, it has a slow leak. Is there anything else I can do to check the servo/assist pump? I applied vac. to it and when I pushed down the brakes it bled off the pressure just as I think it should have after reading the shop manual.

One major deal is with brake pedal travel. The pedal goes half way down to the floor before it even begins to engage. I read about the drum brake adjustments and suspect that the linings are worn (I doubt it) or everything is out of adjustment.

Is the best way to set up the brakes according to the factory service manual?

My deductions seem to leave me thinking that the vac. assist is not working correctly because everything is SO out of adjustment. Is this possible?

Also, what type of brake fluid do I need to use in this car if I bleed the system??

Thanks alot folks, and I hope I can help one of you out one of these days!!

Evan

[240z4u]

Update;

Seems like the brake booster was "stuck" and I freed it when using the vac pump last night. I took it out and it drove much better BUT the pedal still engages pretty low and after the initial push, it feels like the booster kicks in. Is this normal? I obviously have never driven another one of these cars, and if its not normal it sounds like brake adjustment is in order.

Thanks - Evan