Master Cylinder Push Rod
NOTE:
Push rod has an adjustment screw to maintain correct distance between booster push rod and master cylinder piston. If push rod is adjusted too long, it prevents master cylinder piston from completely releasing hydraulic pressure, causing brakes to drag. If push rod is adjusted too short, it causes excessive pedal travel and an undesirable clunk in booster area.
Remove master cylinder to gain access to push rod. To check screw adjustment, fabricate a gauge. See Fig 1 . With engine running and vacuum line connected to booster, place gauge against master cylinder mounting surface of booster. Adjust push rod screw by turning it until end of screw just touches inner edge of gauge slot.