Thread: Trim Hydraulics...

This is for yellow fill cap style and I sure hope this is the one you have. This one is quite simple and fairly cheap to repair.
Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mercury Outboard OEM Parts Diagram for POWER TRIM(YELLOW FILL PLUG)S/N-USA-0G360003/BEL-9934137 &U | Boats.net

This one is for the black fill cap model. More difficult to repair and lot more expensive.

Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mercury Outboard OEM Parts Diagram for POWER TRIM(BLACK FILL PLUG)S/N-USA-0G360002/BEL-9934136 &BE | Boats.net

Another thing you can do, that worked for me, was to remove the cap from the unit and pull out all the fluid you can with a Mighty Vac, or a turkey baster from the Dollar Store, and refill with "Valvoline High Mile Dextron Transmission Fluid Containing Stop Leak And Seal Conditioners". Since it only removes a portion of the fluid, it will take a few "Flushes" over time to get it all replaced. I flushed mine once a year for a couple of years, and it's all good. The leak was gone after the first time. My trim fluid looked TERRIBLE when I first saw it, but now it is clean and no more leak at the top at the rod like yours.
The Valvoline trans fluid can be found at Walmarts, Auto Parts stores, etc.
I believe this may be an overlooked service that many owners don't do. I mean really - ONE QUART could do the job for years.

I will have to give this a try. I went and chatted with a marine shop yesterday, and they said they couldn't find parts, and it was going to be an entire rebuild, and......BLAH, BLAH, BLAH.....WHICH ADDED UP TO ABOUT $1150! So I thanked them for their time, took one of their advertisements pens, and deleted their number from my phone. There has got to be a different way. They also mentioned that Autozone Power Steering fluid is what Mercury uses in that application anyway. LIKE I SAID, poor people have poor ways, and this your suggestion will be next step!

Originally Posted by TheGrandPoohBah

Another thing you can do, that worked for me, was to remove the cap from the unit and pull out all the fluid you can with a Mighty Vac, or a turkey baster from the Dollar Store, and refill with "Valvoline High Mile Dextron Transmission Fluid Containing Stop Leak And Seal Conditioners". Since it only removes a portion of the fluid, it will take a few "Flushes" over time to get it all replaced. I flushed mine once a year for a couple of years, and it's all good. The leak was gone after the first time. My trim fluid looked TERRIBLE when I first saw it, but now it is clean and no more leak at the top at the rod like yours.
The Valvoline trans fluid can be found at Walmarts, Auto Parts stores, etc.
I believe this may be an overlooked service that many owners don't do. I mean really - ONE QUART could do the job for years.

Any tricks to getting the cap off without the "special tool"? I might honestly head down to a boat mechanic, just to see if they could take the top off for me, then go from there!

Originally Posted by mrwillis

Any tricks to getting the cap off without the "special tool"? I might honestly head down to a boat mechanic, just to see if they could take the top off for me, then go from there!

I was referring to the big nut on the side where you put in the fluid, not on the jack, but under the little motor. Channellocks work fine for that. That's where you can get to the fluid.
As for the top of the cylinder, it calls for a special spanner, but you could make one with a 1/4" thick strap and two small bolts that are properly spaced and will fit the holes. A couple of long shinny punches might even work, with Aero Kroil penetrant.
As posted before, rebuild kits can be bought, but the fluid flush trick worked for me.
BTW, you did good to walk away from those clowns that tried to pick your wallet!

Originally Posted by TheGrandPoohBah

I was referring to the big nut on the side where you put in the fluid, not on the jack, but under the little motor. Channellocks work fine for that. That's where you can get to the fluid.
As for the top of the cylinder, it calls for a special spanner, but you could make one with a 1/4" thick strap and two small bolts that are properly spaced and will fit the holes. A couple of long shinny punches might even work, with Aero Kroil penetrant.
As posted before, rebuild kits can be bought, but the fluid flush trick worked for me.
BTW, you did good to walk away from those clowns that tried to pick your wallet!

I was glad to read your response to this. I was thinking about it while mowing yesterday: remove that fill plug, suck out everything I can, then replace it with what you recommended, and eventually it would make it's way through the WHOLE thing, and hopefully do the trick. I am glad we are on the same page. A TON EASIER, and I'm running out of time.

On a different note, that Aero Kroil is AMAZING! It's almost like it crawls into the places other stuff can't. I had an old jeep that I was fixing up. I couldn't get one specific bolt loose....even with an impact. Matter of fact, it broke an 18mm socket trying to get off. I had a man here at the church where I work give me a can of that stuff. He told me to spray it on there, let it sit for a day. Spray it down good again, give it another day. I went out after that second spraying, broke it free with a breaker bar with ease. IT'S EXPENSIVE, but it's worth it. I have a can in my truck, and a couple in my shop!