another brake question

[stafford]

what is 10 lbs residual valve? I see alot of talk on here about it
also are you guy calling the porpotioning valvle the combination valve?
I have just put a New Stock Manual Master cyl. on my car, (figured out my brake pedal problem). I have new calipers, and the wheel cyl on the rear are not leaking, but I noticed that when I am pumping up the brakes and hold it. The pedal slowly bleeds down. I see no fluid leaking so WHY is the brake pedal slowly going to the floor? The Master Cyl. I bought from O'reillys is suppose to be for a manual brake 79 malibu.
your thoughts are greatly apprecatied.

 

[C LOWERY]

A residual valve is used when the master cylinder is mounted lower then the wheel cylinders or calipers. It keeps the fluid from draining from the brakes back into the master cylinder. Anytime that my pedal slowly went to the floor was due to a BAD master cylinder.

 

[stafford]

I was thinking that the new master cyl. could be bad also, I am going to take it back and swap it out and see if another will fix this problem.