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How to fill hydraulic on older mariner?

carso

New member
Hi
I had posted earlier today looking for some help in figuring out what might be going on with my tilt/trim. No luck yet so I thought i would try a different approach.

Here is my story. I have an early 80s 150hp mariner on an Invader boat. The trim up has been sluggish for the last 7 or so times out. This last time it stopped lifting up completely. Once out of the water we had to loosen a line at the motor to depressurize the system so we could tilt it up by hand - heavy old thing! We saw that trimming down pumped oil out of the line but trimming up didn't - Could this mean anything?

Now that it is home I tried pushing the up button again. The motor ran for about 10 seconds and then changed sounds - seems to start to run faster - running empty? Nothing moved. I took the block out that was holding the motor up and it went right down - no resistance.

I want to fill the system up so I can see if anything happens. My problem is likely more than just a lack of fluid but I though it would be a good place to start. 1 to 2 cups ran out when we took the line off - maybe more - it was getting dark. I unscrewed the fill plug and it is full. I ran the motor with the fill plug off and nothing came out but I could still see oil at the top. I couldn't get what I am assuming is the bleed off screw that is just above the fill plug loose - if I did get this loose would this bleed off the air and allow me to fill through the fill hole?

How else could I fill it? - If I take a line off at some point would it suck up fluid?

Also - my new neighbor who happens to be a mechanic (auto) thinks my problem could be a bad check valve - no valves in the lines - anyone know where they are?
Thanks much for your help.

Carso
 
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There are bleed screws that need to be opened in a specific order to bleed these systems. I assume you have the twin ram set up if it's an inline Mariner. You can run the pump all day and not get any air out of the system as the hydraulic line is the only way in and out of the cylinders.
You should probably buy a workshop manual.
And don't listen to auto mechanics, they don't know enough about cars, let alone anything else.

Regards, Andrew.
 
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