I'm stumped help!

[jmorri34]

Ok I know this has been hashed over a million times and trust me when I say I have researched all the other posts and I am stumped. Here goes: The infamous hard brake pedal. I changed from all drum to all disc and EVERYTHING from the pedal to the tires is brand new. I have tested everything I know to test I. E. Vacuum,booster check valve, pushrod is straight,vacuum hose is good,proportioning valve everything. I even did every test CPP says to do on their tech site and nothing, I have to near stand on the pedal to stop. The test for a stuck proportioning valve is negative, I just dont know what to do next. I keep thinking its a bad booster but didnt save the reciept for it( I know dumb me) So I cant send it back to CPP. Anyway, I wanted to see if anyone has any other ideas before I go buy a new booster so thanks for anything!