Much appreciated! I had my parts department order the service manual and after disassembling the power brake housing, I found that one of the O-rings (same one as before) on the lower crossover tubes had been damaged.
Crown sells a reman brake, that's your best bet. It takes a special socket and when reassembling I suggest gluing the oil seal in with pipe cement or you could be doing again. Jack up on side your changing, pull axle, remove big axle nut lock bolts then nut. Count how many threads you see on axle housing because your going to have to tighten back to that point, remove the two brake tubes on back. There are two bleeder screws, one for parking and one for service, get a plastic tube and bucket, cause it needs to be running to bleed and it will shoot oil everywhere. Not a bad job after you do three or four lol Good luck