hi sages- have changed lots of master cylinders since 65 in a variety of cars, but not in one with abs. reason was the same in all of them either leaking out the back where the pedal rod goes or where it joins the brake booster. this led to lost or reduced pedal pressure. 92 volvo 245 has abs. bently and haynes say only difference is the order in which you bleed the wheels if air gets in the abs hydraulic control unit under or in front of the master. never got air in the master or in the lines b/c i bench bled the new master by using the little screw in clear vinyl hoses in each outlet and routing them back to the resevoir which i filled with dot 3( 4 in a volvo) and then pressing the piston in the cylinder. this pumped out the air bubbles through the hoses which were submerged in the fluid and then pumped just straight fluid. i quickly mounted the cylinder and connected the two metal lines but only hand tight. then i pressed the pedal slowly to the floor. fluid spit from the lines which i then tightened and let the pedal come up. then cracked the line nuts again and pressed the pedal down to the floor and again held it. fluid streamed from the lines without spitting and no air. quickly tightened the nuts again.thereafter had full hard pedal and no problems. mechanic told me this method is ok but on abs it is ng and you have to let shop do it $$$ b/c they have mystery tools and gages backyard techs dont have. i dont believe this. my shyster radar went on right away. if you have replaced a master on an abs car i would love to get your take on this . thanks tons oldduke