Found this 'info' on a website that makes killer brake master cylinders etc... called www.CNCBRAKES.COM
 
This is good info - because sometimes we're trying to fix an issue after another issue has already been resolved --- BUT --- the previous brake issue may have caused you to glaze over the pads -- so now no matter what you do - you have poor braking! So look at those pads - are they shinny? OOPS... Do you have big time "race" compound pads and you're trying to use them on the street?? OOPS.... 
 
The best one is the "reverse thinking" -- where a LARGER bore size must be mo' betta.... OOPS --- SMALLER diameter bore size makes MORE PRESSURE not less.... so if you have disc all around -- with MANUAL brakes (all one ever needs!) then you better be running a 7/8" master cylinder -- 1" is okay IF you have power brakes AND good vacuum.... 1 1/8" master is for DRUMS..... 
 
ANOTHER problem I see all the time -- the master cylinder lines are crossed up -- NOT EVERY MASTER CYLINDER HOOKS UP THE SAME.... some use the front reservoir for the front brakes and some use it for the rears.... THE FRONTS should activate FIRST. Check this by taking off the top of the master - have someone SLOWLY press the brake pedal - which reservoir do you see fluid movement in FIRST (by half a nanosecond) ... that reservoir is the fronts....
 
HAVE TO PUSH TOO HARD ON PEDAL
Ain't old cars fun?? LOL

 
Best,
Greg Weld