Can't recall on the o-ring coming with OEM WP. I am in the aftermarket pump, changed with every belt mode. I know the o-ring definitely has its own OEM PN as I have bought them. I have Mistu's ASA parts software that you can download.


Big Truck: 00, 3.5, Endeavor, 5-Spd drive line in hand!
Little Truck: 87, 2.6T I/C, MT, LSDs, Tonneau Top
Her Truck: 03, 3.8, 20th Anniv, 65k
Daughter's: 06 Eclipse, Keeping it Mitsu!
FSMs: MitsubishiLinks.com