Trim fluid for 1994 Merc 40 HP ??????

Workin on a buddy's 1994 Merc 40 hp and it is low on trim fluid. He does not have an owners manual. What type of fluid does it use? Also, some older motors say to use Dexron 2, so does that mean you can use Dexron 3 in those systems also?

I don't know if this one uses engine oil or power steering fluid.

Any help appreciated. He just got the boat and is anxious to get it in the water !!

Re: Trim fluid for 1994 Merc 40 HP ??????

My Merc manual says to look at the fluid. If Red use ATF and newer ATF's are improved versions of older fluids hence will back fit. If clear, use Quicksilver PTT fluid.....from the Horses mouth.

HTH,
Mark

Re: Trim fluid for 1994 Merc 40 HP ??????

Thanks, this may have gotten water in it coz it is kinda lookin brown like motor oil. I wish some one could tell me what an owners manual for this motor calls for.......

Re: Trim fluid for 1994 Merc 40 HP ??????

goblerblaster said:

Thanks, this may have gotten water in it coz it is kinda lookin brown like motor oil. I wish some one could tell me what an owners manual for this motor calls for.......

Click to expand...

If kinda brown it could be old ATF. PTT fluid is almost clear. If I were to guess, I'd go with the PTT fluid as it is specifically designed for pumps, not transmissions and any additive package would surely be to keep rubber seals intact and other than lubrication, that to me would be the most important aspect.

Mark

Re: Trim fluid for 1994 Merc 40 HP ??????

Copy and paste from manual:

40/50 HP
Checking Power Trim Fluid
IMPORTANT: This trim system is pressurized. Remove
fill screw when outboard is trimmed to the full “up” position.
Retighten fill screw securely.


40/50 HP
1. Tilt outboard to the full up position and engage the tilt support lock.
2. Remove fill cap and check fluid level. The fluid level should be even with the bottom of the fill
hole. Add Quicksilver Power Trim & Steering Fluid. If not available, use automotive (ATF) automatic
transmission fluid.((ATF) Type F, FA or Dexron II fluid)

Re: Trim fluid for 1994 Merc 40 HP ??????

goblerblaster said:

Thanks, this may have gotten water in it coz it is kinda lookin brown like motor oil. I wish some one could tell me what an owners manual for this motor calls for.......

Click to expand...

if it has water in it then it will foam up as it goes through the gears and the foam will be milky whitish stuff that takes hours and days to settle back out.

hydraulic oils should be honey colored. if it is dark then there is either carbon or dissolved rubber in it - or somebody used motor oil.

ATF is red in color. only use the types specified. If the ATF has additives they can impregnate the rubber and damage your trim at high pressures.

hydraulic oil is better but you will need a flashlight to see level into reservoir and it is more difficult to find. Even when you find it, the good stuff is $20 a gallon so the mercury PTT price isn't really all that bad.