Merc I/O Losing lube from res. on top of v-6

[maxum1800]

I'm having trouble finding the cause of a leak that is empting my reserve bottle for the outdrive on my 94 Maxum with a 4.3 . At first I thought that it was in the outdrive,but now I know it is leaking into the boat under the motor. I have removed the reserve bottle and filled while capped off and watched for leaks,none. I removed the hose and clamps that lead down to the inside brass fitting and vacum checked hose,ok. I renewed the clamps on install with good fuel injection clamps. Same condition. My outdrive unit stays full of clear clean lube but the bottle empties into the back of the boat. I believe that I can see the 90degree brass fitting and where it tightens into the transom body and feel that that seems dry. It appears that the leak is just below that area. What could be my problem? Could there be a crack in the housing ect. I'm hoping that someone has seen this and has an explanation. I have had similar stern drives for 30 years but this is my newest with a reserve bottle and right now I'm leaving it empty and using it like the old ones with just filling it to the vent hole from the bottom fill hole and it stays that way. Thanks in advance for any light on this subject . Tom

 

[mkast]

Re: Merc I/O Losing lube from res. on top of v-6

Fill the reservoir, pressurize the reservoir with 1 or 2psi, look for leaks.

 

[jerryjerry05]

Re: Merc I/O Losing lube from res. on top of v-6

If you are loosing oil from the resivoir and it's comming into the boat.The front seal on the drive at the yoke is leaking,The transom assy. has a hole from the bellows to the inside of the boat.You will need to remove the drive and get the yoke resealed.Jerry

 

[maxum1800]

Re: Merc I/O Losing lube from res. on top of v-6

Thanks for your quick reply. It makes so much sense now that you say that. So what your saying is if I could see thru the rubber drive boot I would see the lube going into the boat and the front seal which is there to keep the lube in the stern drive must have a leak. I just bought this boat and the last owner said he just renewed the shift cable boot due to water entering the boat ,do you think that it probably got hurt then? I've renewed a transom bearing one time in my 87 citation that had the Alfa 1 and I was able to go that far. To renew this seal do you know if it's the same basic procedure or would I need to go farther? I'd like to do it cause the trim switch wires are in bad shape and I would probably renew all the boots at this time so I should be set back there then if I do all at the same time. Would you know how much is to renewing the trim tab switches as far as routing them thru the transom?Thanks again for the light bulb and I'll wait for your final word. Thanks again in advance Tom

 

[jerryjerry05]

Re: Merc I/O Losing lube from res. on top of v-6

The seal is in the drive.It could go bad from setting.Moisture causes rust,rust causes the seal to go bad.AS far a s fixing you will need special wrenches to remove the top nut.You will need to replace the top u-joint yoke.
Replacing the trim sender can be done,but it aint easy.Buy a manual of some sort.Jerry

 

[Bondo]

Re: Merc I/O Losing lube from res. on top of v-6

Buy a manual of some sort.

Ayuh,.... Welcome Aboard, Tom,...

I agree with Jerry,.... He's leading you Right.....

Btw,....
Here's the factory Manual for it,.....

 

[achris]

Re: Merc I/O Losing lube from res. on top of v-6

If it is the top seal, and I agree with the previous posters that it's the main suspect, then just remove the drive, check that there is oil in the bellows and take the drive to a dealer who has the right tools.... It's not a big job and the seal isn't that expensive... It's cheaper than you buying the tools, and a lot cheaper than you trying to do the job without the tools and destroying the drive...

I don't know how many hours you have on the engine, but at that age the yoke has probably got a nice groove in it. Either replace the yoke, or have the dealer set the new seal 40 thou deeper, so it runs on a new surface....

Chris..............

 

[maxum1800]

Re: Merc I/O Losing lube from res. on top of v-6

Thank you to all you guys for this help,I can't believe how much support you guys have given me and I've only been on this sight a day! I'm hoping that I can help someone myself on this sight to earn my keep. Thanks again Tom.

 

[captiva190]

Re: Merc I/O Losing lube from res. on top of v-6

That was good info, I had a problem like that and it was the rubber seal on the reservoir cap that was bad

 

[achris]

Re: Merc I/O Losing lube from res. on top of v-6

That was good info, I had a problem like that and it was the rubber seal on the reservoir cap that was bad

The original poster said he saw the oil leaking out of the drain hole under the gimbal bearing, not oil dripping down the side of his engine...