Oops, blew gear oil outta top seal!!! Big deal?

[Goblin]

Changing my lower unit oil ( 90 hp Yamaha)in a hurry last night I put in my top vent screw to early and hit pump one more time about a minute later had oil coming out water intake vents. Is this a major? Do I need to replace seal? Inspect? From what I know that seal is to keep water out. Has anyone done this and what did they do! I am still swearing at myself too!

 

[gungadin]

Short answer; -maybe. Either test it yourself or have it tested. Drain out the oil, and remove the leg and remove the propeller. Plug the top (level)hole and apply about 10-15 (no more than) psi of air pressure to the lower hole, while the leg is submerged in water. If you cannot submerge it in water, spray a lot of soapy water in those two areas. Look for air bubbles, where the drive shaft goes into the leg and where the propeller shaft exits the lower section. any air bubbles indicate a leak and most likely a seal failure.

 

[Island Fish Lifter]

Sounds like an upper seal. Might have just blew by the seal lips under pressure, but this wound indicate a worn seal and may need to be replaced anyway. Easiest thing to do is pressure test it in place to see if it holds pressure for an hour or so.

 

[Goblin]

I forgot to mention I did the top seal three years ago as it comes with the full impeller kit and the oil I drained out before my screw up was nice a clean.