The big one should be the 7/16 - 20, and thats generally the input. You can always pour some brake fluid in and give it a tug to see which hole it squirts out of.

Quote
Carl S
The big one should be the 7/16 - 20, and thats generally the input. You can always pour some brake fluid in and give it a tug to see which hole it squirts out of.

That's the only safe way, why believe a buncha numbskulls here?
Pour some brake fluid----make sure its fresh and exactly the same as you will be using, the look carefully straight into the 7/16 port.
Have a friend pull the lever a full stroke (cause there might be air) while you hold a flashlight between your teeth.


Thanks Carl, sometimes it's good getting advice from real mechanics like you.

Sorry. 3/16-24 output and 7/16-20 input and use banjo bolts. I have the same master.