You can unscrew the gland nut with the stop tap still in place on the pipe without the stop tap leaking. Unscrew the gland nut push it up to the head or top of the spindle. Apply a few rolls of PTFE tape to the bottom of the spindle then, push the PTFE into the stuffing box, the bit the spindle goes into, and replace the gland nut. That's it.
CARL MIDDLETON, May 2008