Mercruiser Trim/ Tilt fluid Help Please

[aerialimage]

1994 Rinker 18' Boat
Mercruiser IO 3 ltr I believe! 4 cyl.
My Trim Tilt fluid looks Milky and now works slowly, I think Water has entered the Vented cap and contaminated the FLuid! I have searched the forums and found People using ATF Type f, ATF Dexron, 30 wt motor oil, 10-30 motor oil, and 10-40 motor oil! One post said not to use Trans fluid due to its Detergents?????? I purchased the boat used and do not have a manual so any help Would be Great! Thanks

 

[Don S]

Re: Mercruiser Trim/ Tilt fluid Help Please

Here is the cure for your manuals.
http://www-alt.mercurymarine.com/mnetdata/sisdata/srvcovr.pdf

#14 for your drive and trim system
#13 for your engine.

10W30 or 10W40 is what Merc recommends if you don't use their Trim Tilt oil.

 

[Bondo]

Re: Mercruiser Trim/ Tilt fluid Help Please

Ayuh,.........Fact of the matter is,...... Any 1 of those oils will work Just Fine...........

The Hyd. pumps used with trim systems are the Simplest of systems.......
Pretty much Any Oil that'll pour like a 50W or Thinner will work without issues..........

Read through that manual that Don gave you,.......
You'll see how to take the lines off the rams,+ Pump/ Purge the Watery oil out of them,.........
Then cycle some oil thru the pump to Clear it of the contamination too......
After you've drained,+ refilled the Reservoir of course.....

Btw,........

Welcome Aboard to the forums here at iboats.com........................

 

[aerialimage]

Re: Mercruiser Trim/ Tilt fluid Help Please

Thank You I now know what to use and will not be worried about if I used the wrong Stuff!
Now to find the easiest lines to pull I am thinking since the entire system needs flushing anyway, I may be able to just pull one of the lines on the pump and cycle the pump in whichever direction makes that the return, then of coarse pull the other when I am ready to send the pistons the other way making the opposite line the return! I will have to put my eyes on the pump to figure out the logistics! Thanks for all the great help!
Hope I can return the favor some time.

 

[Bondo]

Re: Mercruiser Trim/ Tilt fluid Help Please

Ayuh,......

I'd be attempting it from the junction at the bottom of the transom assembley, outside the boat........
It's where the 2 lines go to 4 lines.........

Hope I can return the favor some time.

Ayuh,......
Hang around here long enough,+ Somebody will ask a Question that You know the Answer to.........

 

[aerialimage]

Re: Mercruiser Trim/ Tilt fluid Help Please

That sounds good, I have not had the time to get over there yet but Hope to get to it real soon. It is Cold here now! Hope There is not enough water to cause freezing Problems, I'll post an update when I finally get over to the boat and get it done.
Thanks for the help!

 

[rodbolt]

Re: Mercruiser Trim/ Tilt fluid Help Please

freezing isnt the issue, the issue is the hydraulic pump and valving just wont tolerate water. tends to make shiney parts rust.
you also need to replace the old style flat cap with a vent hole,brilliant engineering idea for a boat, with the later style cap that vents through the threads.
dunno which engineer designed that cap but I guess he was desinging stuff that doesnt get wet.