What does this piece of SH(*&T do? It is leaking on me and then i forgot to bleed the used pump i just got from the junk yard and it shot craps. So anyway, i need to know what causes these to leak on a pump. It is the little hole that faces the engine block on your PS pump assembly. I was thinking of putting a bolt in there to stop the leak but wanted to know the ramifications first before i did something else and destroyed my box next. Pumps are cheap $15 but the boxs arent.