Filling Lower Unit Prob???

[michaud500]

Hey everyone. I have a question about filling my lower unit, its a 1969 mercury 500 # 2629264. I opened both the Vent screw and the Fill Screw. Screwed in the filler tube from the container of oil and pumped the pump. I think some oil got into the unit but not sure. Isnt the oil supposed to come out the Vent oil above the fill hole??? There was pressure built up in the pump from pumping the oil into the unit. Any ideas? Am I to impatient?

Thanks

 

[Texasmark]

Re: Filling Lower Unit Prob???

You are doing it right. Pump if you have a pump, or squeeze the tube if it is in a tube until you get solid oil (very few bubbles) out the vent hole. While the filler is still in the lower hole, insert and tighten the vent screw then remove the filler and insert the fill screw and tighten.

Mark

 

[ThumbPkr]

Re: Filling Lower Unit Prob???

Make sure that you have the correct bleed screw.There is a plug into the water jacket in that area that is plastic and could be mistaken for the lower unit vent.The vent screw will be metal.Ron G

 

[michaud500]

Re: Filling Lower Unit Prob???

Thanks for the input!! I am new to the boat world so a little patients please. When looking at the lower unit there are two screws one that is lower than the other. I attach the pump to the lower unit than unscrew the higher up one. Fill and replace screws in opposite fashion. The problemis that I cant get any fluid into the lower hole. Is it plugged???

 

[Mi duckdown]

Re: Filling Lower Unit Prob???

Are pics possible.?
Your procedure is correct.

It is not rocket science. No offense.?
both fill and vent are ss steal with fiber gaskets/washers. and Must be replaced.
Sometimes they stick to the lowerend and have to scraped out to get a good seal.

 

[Texasmark]

Re: Filling Lower Unit Prob???

The problemis that I cant get any fluid into the lower hole. Is it plugged???

First, with both plugs out, you should have had old oil drain out. Did it? If it did, then you should be able to plug in your filling nozzle from your new oil container and get the LU to accept the oil. If it didn't then is the old oil stuck in there, like it jelled from lack of being serviced?

What are you using for an applicator????? tube or pump with hose? Pump with hose is a walk in the park...just stick the hose in and pump.

On the tube, I squeeze the tube and as I do, I roll up the bottom of it, like toothpaste, which helps to get all the oil out.

Mark

 

[michaud500]

Re: Filling Lower Unit Prob???

I dont have any pics yet. Now that I think about it there use to be a washer that was with the fill screw. It is not there know. The previous owner supposedly had the motor and all serviced in the spring on winterized in the fall. I am using a pump type pump that I got from Gander along with the oil. The pump work fine I tried pumping it before I connected it to the unit and fluid did come out. Should I tear apart the lower unit? I was hoping to wait until winter to do maintenance. But sometimes ya gotta do what ya gotta do.

Thanks for all of you help!

 

[Sunfish12]

Re: Filling Lower Unit Prob???

Squeeze some oil in at the vent screw(for test purpose only) and see if it drains at the fill screw. If it doesn't drain you have a blockage.
As Thumb said, some lower units have 2 screws above the fill screw, one is a vent and one is a flush. Double check.

 

[Texasmark]

Re: Filling Lower Unit Prob???

As Thumb said, some lower units have 2 screws above the fill screw, one is a vent and one is a flush. Double check.

My '02 90 3 cyl has 3 screws: 1 drain below the gearcase and two on the starboard size over the anti-vent plate. Manual says to take both screws out to vent and fill oil till the front has flow and install the screw and then continue filling till the aft has flow and install that screw. Then remove the filling device from the lower hole and install that screw. Ensure all 3 have the blue washers installed.

Mark

 

[michaud500]

Re: Filling Lower Unit Prob???

I tried filling from the vent screw. It too oil but it started coming out the water(vents) intake above. Then when I removed the fill tube oil come out, fresh. Must be full!

 

[j_martin]

Re: Filling Lower Unit Prob???

The oil drain/fill screw is way down at the bottom of the bullet. The two you have out are the oil vent screw and the water jacket plug.

Oil, should drain out of the lower hole when it's unplugged. There also should be a magnet on that plug, maybe with a little fine metal on it.

When you fill it, there should be minimal resistance. When oil comes out the vent, quit filling, take the filling tube off, let about an ounce spill out as you put the plug in. You want an air bubble over the LU oil for expansion. Put the drain/fill plug in first, then the vent plug. Use new gaskets.

hope it helps
John

 

[michaud500]

Re: Filling Lower Unit Prob???

I am a dumb a34! I was using the wrong holes. I needed to look at the front of the transmission. Not the side, was using the vent hole and the flush hole. Got it know and all is well. Drained out nice like no water a little silvery ness and refilled. Thanks for everything!!!