Also, when bleeding the brakes, I believe you need to loosen the brakes all the way on the rear so it forces any air bubbles out. (best to read through the shop manual).
I made a power bleeder from a cheap 1 gallon sprayer I bought from Lowes. It pumps up t0 40 PSI and worked great! There are 2 bleeder screws on your hydrovac unit, need to bleed those in the proper order, before any of the wheel cylinders (see link below).
http://chevy.oldcarmanualproject.com/shop/1955truck2/55ctsm0528.htmI believe 3B is correct on the wheel bleeding sequence. The main thing to remember is bleed the longest line first, working to the shortest one last. The 55 manual has a different sequence than the 58 manual but, the hydrovac is on the opposite side so, that makes sense.
