I'm stuck with intermittant crappy brakes. It's not air in the brake lines.
It's a problem with vacuum. My local Volvo maven suggested checking the brake booster for a vacuum leak.

He gave me a gizmo to plug into the checkvalve port and draw a vacuum on it
and see if it holds up. I can do that with my harbor freight vacuum brake bleeder that has a gauge for vacuum. Comments?

This is wonderful to use that thing since I think it's better to pressurize
the master cylinder and bleed the brakes that way.

Comments appreciated,

Bill