Purging trim fluid from the system

[TheRussian]

Hello all,

I am attempting to purge all of the trim fluid from my trim system on an Alpha 1 Gen 2 because of the milky oil (water got in from the top of the reservoir, the system is working fine). So far I have taken off and cleaned out the reservoir and replaced the metal filters which I found to have been torn up. I am not sure how to purge the lines and the rams. The Merc manual does get into purging air but it requires some plugs (don't have) and I also HAVE THE DRIVE IN THE TRAILER position - the manual states to have in trimmed down. I had found Bondo's old instructions on a different site - disconnect the lines on the transom (4 lines total I assume), move the drive up and down by hand and then run the trim pump up and down. Then reconnect.

Is this procedure correct and is it really possible to move the drive up and down by hand after the lines are disconnected?
Also, when I reconnect, does the drive have to be in the initial position when I started the purge?

Thanks in advance.

 

[dubs283]

just crack the lines where they attach at the rams, does not matter which ones

as fluid leaks out past the threads the drive will lower, once all down remove the lines altogether and lift the drive up by hand to purge all the old oil out

reconnect all the lines, fill the reservoir and run the drive up and down multiple times, check fluid level with the drive in the full down position and fill as needed

the pump and system is self bleeding, four cycles up/down is sufficient to bleed and top off the reservoir

 

[TheRussian]

Thanks,

Should I fill the reservoir and run the pump before reconnecting the lines to clear any oil that is in the line between the pump and the transom? Or can I run the pump w/o any fluid to clear?

 

[dubs283]

Should I fill the reservoir and run the pump before reconnecting the lines to clear any oil that is in the line between the pump and the transom?

wouldn't hurt

 

[Outsider]

Or can I run the pump w/o any fluid to clear?

Not sure how good that would be for the pump. Bleed the pump and hoses (usually meaning trim UP), keep the reservoir topped off until all contaminated fluid is purged, then reconnect and cycle the system. May take several cycles to purge all the air and restore normal function ...

 

[UncleWillie]

The cylinders are in parallel, removing both hoses from one side is the same as removing all 4.
The pump is a gear pump you will not hurt it by running it dry but you will also not be moving any fluid.

The cylinders Pistons have bypass valves that operate when the DOWN limit is reached.
Keeping the pump ON against the DOWN Limit will purge any Air or Bad Oil.
If the UP hose is removed while doing this, the Bad Oil will not be returned to the reservoir.

 

[TheRussian]

UncleWillie,

So what you are suggesting is removing the UP hose only, filling the reservoir and keep the down button on for a while on the trim control until the oil runs clean? Will this also take care of the DOWN hose?

 

[UncleWillie]

I haven't tried it but, in theory, that should work to flush everything.
I would still drain as much as possible before flushing.

The Cylinder Piston Bypass Valves are included to allow the entire drive to swing UP if you ever run over a large log or hit a substantial rock. If you force the drive backwards the pistons will bypass Oil and allow the drive to pass over the obstruction instead of tearing off the transom.

I once tried it by hand but I think you will need Arnold and the Hulk to actually move it.
The pump will be straining to bypass the pistons so it may take a while.
Also you can't be sure both cylinders are bypassing so you may need to do one at a time.

Watch your reservoir level so you don't pump it dry.
Let us know how this works.

 

[JASinIL2006]

I had milky fluid in my trim pump and had to purge them, too. I followed the directions in the service manual under "Bleeding OUT/UP Trim Circuit" and "Bleeding IN/DOWN Trim Circuit" and it worked well. I had to find a bolt to fill in for the plug (I forget the size and thread count off the top of my head, but I just measured the diameter of the hose fitting that came out of the hole to be plugged and found a bolt that looked close, and it worked). I had to repeat the procedure a couple of times before I stopped getting milky/foamy fluid, but it worked fine. If the drive isn't in the right position, I'd just fill the pump reservoir and lower the drive and pick up with the instructions from the manual.

The worst part, other than wasting a couple of quarts of oil, was trying to get those hose fittings off - and then back on - when everything is all oily. Otherwise, it was pretty easy. You do need to have sufficient clearance to run the outdrive through it's full trim range; in my case, I had to jack up the trailer so I could trim it in fully.

 

[TheRussian]

Thanks for the suggestions. I am at work tonight until late but I will be working on this in the next couple of days. I will let you guys know how it went.