86 Ranger,
#1. First I replaced rusted out line for the rear breaks from the fuel pump back to connection on axle (only I had to shorten the length by 2 inches - used 2 pieces stock line, do it yourself bend to fit) I bled the Master and system all but passenger rear, broke bleeder.
Question: how much if any will this effect the brakes effect, is it not about 20 lbs per square inch less pressure applied to the rear then before, I forgot the math and measurements. the line was 3/16 line?
#2. all but bleeding the right rear, the system worked fine no air, except the sized front caliper.. Then I replaced the right rear cylinder and rebuilt the left front caliper, and replaced the rotor not too rusted, mostly I believe it needed grease on the sliding parts, and the boot was hard, just fell apart, plus the rotor was warped. Now I have used a whole bottle 32 oz. of fluid and still have air, What is the most likely cause? Oh most of the air comes from the back brake lines.
#3 Any ideas or information on ( Valvoline SynPower Synthetic Formula Brake Fluid)
It is amber /clear in color and states on the label exceeds dot 3&4 and is compatible with conventual Brake systems. I got mainly for my clutch. Then for the Brakes I mixed it with the old regular dot 3 Preston Brake Fluid. Should be OK Right?
#4 ( did not use genuine ford seal for replacement) When I replace my Rotor the new
rear seal ( rubber seal it's self - was shorter, but by comparison it reached the thick area of taper of the rotor shaft, but did not go all the way to the end , and seat against the backing plate area.
Is this normal, did they change the size of the seal, or is the generic seal just less.

 

If you have gone through 32 oz. of fluid and still have air I would look closely at the master cylinder. Air can get sucked in on the release stroke if the seals are bad.
CB