HI , am pravar Sharma from India .usually some rubbish Parker pen leak from near the nib.I have an idea to fix it .just apply some fevicol(the white glue )around the body that is near the tip as shown in the picture.Then keep it somewhere for sometime and when it dries up you are ready to use it!!!!!!! actually i am not good at clicking photos so thought to express it by using paint app.sorry!!!!!!!while applying fevicol it should only be put around the leaking point.