83 deville brake problems.

[bob vila]

bear with me here, i am new to this forum, although i do understand how these forums work, as i moderate at a different one. i will not mention the name of that forum, (advertising rules prohibit that i am sure) but i will mention that it has to do with personal computers only.

now to the question.

i am working on an '83 Cadillac coupe DeVille. The cam had gone flat, and after many hours, im glad to say it is running like a champ again.
but, this brake problem is perplexing me.

the car had about 10% brake pressure, and was almost impossible to stop, even while moving it in the driveway. the pads and shoes are still within tolerances, and they show normal signs of wear. the brake system was bled, and barely any difference was noticed. then, the booster was replaced, and that also made amlost no difference. then the master cylinder was replaced (and bled), and the system was again re-bled, and then re-bled again just to be sure.

the brake pressure is still nearly zero, although the pedal now does feel stiff. when you push on it, it almost seems to push back at you. the car can still barely be stopped. if it is in gear, it will continue to creep along, no matter how hard i am stepping on the pedal.

i have checked, and all the lines are ok, no signs of leakage, and when bleeding, there is a good flow of fluid to each bleed valve.

the wheel cylinders are also not leaking, and neither is the splitter.

i have worked on cars since i was 14, and i have never had this sort of problem with any car i have worked on.

can anyone tell me something i might check to see if the master cylinder or booster are bad? (rebuillt units can sometimes be bad, although the booster was a new part, the master cylinder was a reman.)

i am open to suggestions, and will check anything you suggest, as i am getting quite irked, and would rather just give the car away rather than fix it, but after sinking 1000$ into this thing including parts and man hours, i cannot really do that.

it also would be immoral for me to sell it without brakes, so untill the brakes work, i am stuck staring at it like an idiot.

i give thanks in advance to anyone who wishes to help me with this obnoxious beast of a cadillac. (has been nick-named the Battle-ack, since this thing has been a battle for us the entire way through working on it.)

[bob vila]

it has been two days, and no reply, so im going to bump this thread.

[RickYaMe]

is vacuum chech valve for booster in backwards ? just a thought ...

[JOEROC]

check the proporsion valve that your lines run into there is sometimes a reset button on them that pops out or it could just be the valve itself.

[bob vila]

well, it has been a while, but the car still has problems, i will go to the house of the person who is holding it and check that.

thank you for helping.

the vaccuum valve is in correctly.