blu3fan

car is a 92 eg with integra rear disks running the stock eg booster and prop valve
okay so last night my brakes almost stopped working.
took a look this morning to find not one leak. anywhere. brake fluid reservoir to be almost empty. needless to say i refilled it. and drove around my house pumping the brakes.
no leaks still.
pulled the master cylinder off the vacuum canister to find fluid inside. my roommate told me that their shouldn't be any fluid inside and perhaps an o-ring has gone. so i should buy a rebuild kit.
or since im running the integra rears should i spend the money and get the integra booster and prop valve since im gonna have to bleed everything now. is there a big difference between eg and integra valves ?
also a problem ive had since i bought the car is at a stop the brake pedal isnt solid it slowly crept down loosing pressure. i had originally assumed this was due to me missing the prop valve but now im not so sure. since i may have a leak in the vacuum canister.
thanks for any info.

Str8EJ

your master cylinder is shot.
the least expensive option is to replace with an exact same part so you know there's compatibility with your brake lines and booster.
if you're looking to upgrade your m/c, be sure to do plenty of research.
difficult to know your options without knowing what kind of brakes you already have (abs, ex/dx knuckles, etc.)
don't drive your car until this is fixed. it's a hazard to yourself and everybody else on the road.