Trim pump overhaul/install

[Oshkosh1]

Hi all...

When I bought my boat, it had set for a few years. Although in almost perfect condition for it's age(including only 400hrs and still the OEM plugs/cap/rotor etc...) I've run into a few age related corrosion issues. One being the trim. Last year I did get the trim working pretty well including calibrating the gauge...but now it will not raise. At first, it started intermittently then I had to use the "Trailer" button(both handle mounted) to get it to raise up underway because the "UP" button didn't work(just clicked). NOW, although it does "click"...even the trailer feature won't do it. Going down is no problem and the motor works great headed that way. Sooooooooo...I just removed the whole pump/solenoids in the hope that I just have a bunch of bad connections...which wouldn't surprise me.

When I get it all cleaned up and ready to install...do I need to bleed the hydro's at all? I tried to limit the amount of oil loss out of the individual lines but obviously there was some.

Searched but couldn't find anything specifically regarding any bleeding necessary...

Thanks again!

 

[harringtondav]

Two issues come to mind. A bad trim limit switch can keep your up switch out of the circuit. That sounded like the first part of the story. A bad up solenoid may cause the 'click' with no motor noise. The solenoid is the same as the engine remote start solenoid - fyi.

My merc. manual says the trim system will eventually bleed itself, assuming you haven't lost a lot of oil from cyl. rebuild,etc. So it sounds like you'll be OK. I mostly purged my cylinders after a pump change-out, and milky water contaminated oil in the system. I didn't do a lot, if any bleeding, and after a few pump skips and burps, my system is working fine.

 

[TurtleTamer]

The pump will bleed itself unless you've emptied the rams, and then you'll have to follow the very specific bleeding procedure (which is fairly simple, once you do it).

The motor usually isn't the issue and is pretty easy to overhaul. If it's the powerdyne type with plastic reservoir, even easier. Don't mess with the pump assembly as the relief valves are factory set.

It's likely your solenoid that is the issue, and if it clicked at all while pushing the "up" button then it shouldn't make a difference when you push the trailer button. If it's the limit switch giving you issue, then it won't even click.

 

[wahlejim]

A couple of full cycles on the cylinders usually does the trick

 

[Oshkosh1]

Thanks guys! I'm in the process of pulling every connection/solenoid off and cleaning/wire brushing/greasing them all to a "high gloss" shine!

The boat is on my lift so it seemed to be pretty simple to just pull the whole thing...which I highly recommend anyone else do as well if it seems that the entire thing may need a good cleaning.

I'll get it cleaned up and put back in tomorrow more than likely...

 

[Oshkosh1]

Got it done...

 

[Oshkosh1]

Got it in and running well. So far as the "lessons learned"?
1. Definitely remove the entire pump if at all possible. It took me less time to pull the pump(5 screws to the deck) than it did the first time I got in there and messed around with trying to clean wires especially on the "Down" solenoid. Removing the pump/reservoir made getting to the solenoids much easier. IF you can't get the entire pump assembly out(due to dry rot/access)...I'd look into at least taking off the two hydro lines and the two 9/16" bolts mounting the pump to the frame and removing that. They'll be "blind" but they're large enough that it shouldn't be too difficult to reinstall by feel. That will open up all of the wiring to be much easier to clean and tighten.
2. A cordless Dremel with a wire wheel is your best friend to clean/shine everything up.
3. NOW is a good time to get behind the pump to the area which is rarely accessed and clean it all up.
4. Super Clean® is your second best friend...
5. Cycle the drive in/out a number of times to purge the air. I got some strange sounds at first but after about 5 complete cycles it sounds like it should.

Thanks again for the help and good luck if you're reading this...You got this!

 

[harringtondav]

My hyd unit stopped pumping last summer after 21 yrs of good service. I was at our river house & didn't have my manuals or hyd gages to diagnose. I googled the Merc p/n & found a $260 complete new unit on Amazon. Once I'm free from honeydoos I'll see if I can fix it. I love spares.