Hey guys, I was having a problem I supposed the brake booster, weaker breaks with the wishing sound of air escaping, then the brakes went out, to the floor, look no major leaks, full master, friend said it was the master bypassing which is a common problem with these cheap Chinese masters, I go to bleed the passenger side front and rear and no brake fluid coming out???

What could make the breaks go out at the same time front and rear, I get the distribution could have a problem but on both?

Any help would be apreciated

1985 Ford F150
300 6
1/2 ton 2 wheel drive standard