water in lower unit

[patrick4266]

I have a 1970/ 85 hp rude model 85093. I removed the bottom lower end grease screw and a small amount of water came out. Should i remove the lower unit and try to fix the leak? what gaskets or seals do i fix? Is there any tricks or something special i should know on this motor? This will be my first attemt to work on a boat motor but I am a auto machani so I understand motors, just not out boards. also should I replace the impeller while i am there? I bought the evenrude service manual from abay so I have that to go by but I still need some advice. thanks

 

[tashasdaddy]

Re: water in lower unit

there should be a washer/seal on the drain and vent plug. they should be changed everytime the plug is removed. you do know you fill from the bottom until you get oil out of the top vent, then put the vent plug in. then the bottom. i would install new washer/seals and check the lower periodically.

if you don't know when the inpeller was last changed, do it now. careful of the wiring to the lower unit, make sure it doesn't get against the drive shaft or exhaust housing.

 

[patrick4266]

Re: water in lower unit

Is there a seal around the propeller that needs to be changed? So you think all i need to to is replace the screw gaskets? What kink of sealer do I use around the housing as I was reading that I have to use some.

 

[tashasdaddy]

Re: water in lower unit

i usually take a little black form a gasket, on my finger, and run it where the rubber seal goes around the outside of the housing, to hold that seal in place.

there are several seals, in the lower unit. but the ones i mentioned are #1 cause of the slight water intrusion. replace plug the seals, Johnson/Evinrude dealer, then check after a run or two, buy a 1/2 dozen seals, and remember where you put them.

you can see the complete parts list and diagrams here: follow prompts

"http://www.evinrude.com/en-US/Accessories/Literature/?popup=true"

 

[HighTrim]

Re: water in lower unit

Im sure by the sounds of it, the drain and vent screw gaskets are in need of change. When I go to the marina, I buy a handful of them and change them each and every time I remove 1 of the screws. The water pump will be no problem for you, being a mechanic, especially with the aid of the manual. If after a few runs with fresh lower unit oil, you still find it to me milky white, a sign of water intrusion, you will need to pressure test it.

To pressure/vacuum test a lower unit:

a) drain the gear oil
b) use an appropriate adapter with a gauge tee'd in to apply pressure or vacuum. No more than 15 psig for pressure. You can use a bicycle pump or any other compressed air source for pressure. For vacuum, you need a vacuum pump.
c) LU should retain some pressure or vacuum for 45 minutes minimum.
d) If pressure doesn't hold, submerge LU in water to find leak source or spray it with some dish soap and water. [possibilities: drive shaft seal, prop shaft seal(s) (usually two), shift shaft seal and the fill/drain screw washers.]
e) replace offending seal(s) as required.

 

[patrick4266]

Re: water in lower unit

Thanks guys, great advice.