Find an empty 15-lb. Freon tank and bracket it somewhere out of sight, like under the bed, then run a big vacuuum line to it, 1/2" diameter or larger, by cutting the original shutoff valve out and installing a grommet. That's how the old Hydrovac units on big rigs stabilized the vacuum, and I can't think of any modern booster at the master cylinder that would require more vacuum than a Hydrovac.
Jerry
