1990 Chevrolet 1500 Pickup Q&A

1990 Chevrolet 1500 Pickup Question: brake master cylander

when you mash brake padel air comes back through mastercylinder has new master cylinder -
Answer 1
What do you mean air comes back through master cylinder? Was it bench bleed before it was installed? -
Answer 2
Did you replace just the master cyl. or did you do the booster also? -
Comment 1
and is their a bad hose or line. causing a leak -