If you google "bench bleeding" you'll find it has been explained many times. Bench bleeding is the only way to ensure all the air is removed from the master cylinder.

You say "I know everyone always says to bench bleed....". You reckon everyone might be wrong? wink (Said with a wink. Not trying to be a smart you know what.)

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.