With that new master, true, the rod have to be adjusted due to the valve inside.
did you replace the slave? usually it's a good idea to replace both. For the slave could have a bad gasket seal around the piston - why you're losing pressure.
Crawl underneath and lift the boot away from the slave case. See fluid..slave is shot.
I have an old fashion way to bleed: open up the spit on the slave and let the old fluid pour out and chase behind with new fluid. Close the spit and fill the fluid bottle full. Then open up the spit for a bit to get a good stream of fluid, then close the spit. Fill the bottle full again.
Now, grab a buddy (or like with me, get the wife to help me) and have them sit in the driver's seat. I tell them to pump up the pedal until the pedal has pressure behind it, then hold it down tight. I tell them when I open up the spit, that pedal is gonna collapse and NOT TO LET THE FOOT off the PEDAL, for if they do, I have to do it all over again.
I open the spit, "spoosh" a shot of fluid comes out and the pedal is mashed to the floor. I close the spit and tell them to pump up that pedal to pressure again..and then HOLD IT. I open up the spit, "spoosh!" another shot of fluid comes out. I close the spit and have them pump up the pedal. This time I can see the slave being activated with the pedal pressure... "Dang, got the thing bled good!"
Works every time ... and I do the same with brakes.
Okey, so I'm old....but...been there and done that a few too many times...and it works every time.