Originally Posted by WRXFanDave
When you take it apart, check to see if the big one is damaged like it got pinched. There is the tiniest of grooves around the big ring and if it's not seated right, the o-rings will get sliced (someone posted this a while back. As far as I know my FEP rings are doing fine. Do keep us posted.
The o ring came out 100% undamaged, looks good as new. The top was leaking as well as all around the case. The bolts were tight enough too !
Reinstalled last night with regular thicker black o rings from hardware store, so far so good.. if this thing leaks again however Im going w a new or reconditioned pump for exchange.
*!*!* 1 week later not leaking anymore with a black buna-n style o ring, thicker and seems to have sealed great!