Water in trim fluid

[JASinIL2006]

In prepping my boat for the season, I noticed the trim fluid was rather milky looking, so I extracted it from the reservoir, put it a jar, and sure enough, some water (a tablespoon or two) separated from the fluid.

The manual recommends replacing and flushing the system, which I was planning to do after the outdrive is back on the boat.

Yesterday, I installed the outdrive, and after it was on, I noticed a small pool of fluid under the drive. It turns out it was trim fluid (must have been what was left in the lines) and it was leaking from the fitting where the down trim line attaches to the rear of the piston. (The 'down trim line' I'm referring to is the the stainless steel tube that runs the length of the trim piston.)

I inspected the fitting where the down trim line attaches to the rear of the piston and it was loose. Since I plan to flush out the system anyway, I loosened the fitting the rest of the way to see what would drain out, and it looked like a little water (a half-teaspoon or less) and some milky fluid dribbled out. After it stopped, I screwed the fitting back into the piston.

My questions:

1. Is it possible that the loose fitting where the tube enters the fitting could be source of water into my system? I don't fully understand how the trim hydraulics work, but I thought the system is pressurized, which would make water intrusion through a fitting unlikely.

2. The manual doesn't mention doesn't provide many details about attaching the 'down trim hose' to the trim cylinder (I thinks it just says "attach DOWN trim hose"). Is there any sort of sealant or dope that needs to be applied to the threads on those fittings?

3. I inspected the trim cylinder, trim hoses and all the fittings for any signs of damage from water freezing, but everything looks OK. Other than filling the system with fluid and flushing it, is there anything else I should do? The trim pump and lines look OK (no leaking fluid, etc.). The boat was outside over the very cold winter (although the outdrive was in my basement), but I'm thinking/hoping the any water in there that froze likely had room to expand.

I plan to refill the system and run it, then flush it until I no longer see any evidence of milky fluid. Anything I'm missing?

Thanks!

Jim

 

[alldodge]

Re: Water in trim fluid

In prepping my boat for the season, I noticed the trim fluid was rather milky looking, so I extracted it from the reservoir, put it a jar, and sure enough, some water (a tablespoon or two) separated from the fluid.

The manual recommends replacing and flushing the system, which I was planning to do after the outdrive is back on the boat.

Yesterday, I installed the outdrive, and after it was on, I noticed a small pool of fluid under the drive. It turns out it was trim fluid (must have been what was left in the lines) and it was leaking from the fitting where the down trim line attaches to the rear of the piston. (The 'down trim line' I'm referring to is the the stainless steel tube that runs the length of the trim piston.)

I inspected the fitting where the down trim line attaches to the rear of the piston and it was loose. Since I plan to flush out the system anyway, I loosened the fitting the rest of the way to see what would drain out, and it looked like a little water (a half-teaspoon or less) and some milky fluid dribbled out. After it stopped, I screwed the fitting back into the piston.

My questions:

1. Is it possible that the loose fitting where the tube enters the fitting could be source of water into my system? I don't fully understand how the trim hydraulics work, but I thought the system is pressurized, which would make water intrusion through a fitting unlikely.

Yes, the trim systems is a hydraulic cylinder which oil is pushed under pressure against the inner piston. When fluid is being forced in one direction, it is being sucked out the other (so to speak). With your fitting being loose, this will allow water to enter.

2. The manual doesn't mention doesn't provide many details about attaching the 'down trim hose' to the trim cylinder (I thinks it just says "attach DOWN trim hose"). Is there any sort of sealant or dope that needs to be applied to the threads on those fittings?

The hose on the rear is actually the line which causes the cylinder to bring the drive up (or out). Not that it matters in your issue. There is no sealant which goes on the fittings, you can use some anti seize, but nothing is required.

3. I inspected the trim cylinder, trim hoses and all the fittings for any signs of damage from water freezing, but everything looks OK. Other than filling the system with fluid and flushing it, is there anything else I should do? The trim pump and lines look OK (no leaking fluid, etc.). The boat was outside over the very cold winter (although the outdrive was in my basement), but I'm thinking/hoping the any water in there that froze likely had room to expand.

I plan to refill the system and run it, then flush it until I no longer see any evidence of milky fluid. Anything I'm missing?

Thanks!

Jim

Just fill and flush and you should be ok unless something shows up which you have not noticed. There could be some crud in your cylinders which need to be flushed out. I could take a bit of running to get it all out. Crack each line and run the pump in short bust until it becomes clean. Then refill and go for it

 

[JASinIL2006]

Re: Water in trim fluid

Perfect! Thanks!

Jim

 

[JASinIL2006]

Re: Water in trim fluid

I did a complete flush and fill as described in the service manual, only to have the fluid get all milky again when I ran the drive up and down. Must have been some crud in the cylinders, even though I did all the stuff that's supposed to purge them. Guess I'll repeat the process again tomorrow to see if I can get it to stay clean.

Not a hard job, but a bit messy...

 

[MarkSee]

Re: Water in trim fluid

Sure one of the hoses isn't compromised letting water in?

How I tracked down which hose was leaking on my Maxum was to have it on the trailer with my son at the helm operating it up and down while I carefully watched the hoses and then could see which hose fluid was leaking out from. The naked eye could not see a hole but having it under pressure provided the needed info.

Mark

 

[tazrig]

Re: Water in trim fluid

If the lines (ss hoses) are original to the boat they are 17 years old and may well need to be replaced, especially if you are running in salt water. If you find one is leaking replace all 4 of them. The other 3 won't be far behind.

 

[JASinIL2006]

Re: Water in trim fluid

Sure one of the hoses isn't compromised letting water in?

How I tracked down which hose was leaking on my Maxum was to have it on the trailer with my son at the helm operating it up and down while I carefully watched the hoses and then could see which hose fluid was leaking out from. The naked eye could not see a hole but having it under pressure provided the needed info.

Mark

I don't know for sure the hoses are OK, but I don't see telltales of any leaking from them... and the boat isn't in water, so anything that got in the new batch of fluid I put in yesterday must have already been in the system. I've been working on this myself, but I'll have a helper run the trim switch while I watch the hoses, etc. If I had a leak in a hose, I'd expect to see some evidence of when system is operating and pressurized, yes?

 

[JASinIL2006]

Re: Water in trim fluid

If the lines (ss hoses) are original to the boat they are 17 years old and may well need to be replaced, especially if you are running in salt water. If you find one is leaking replace all 4 of them. The other 3 won't be far behind.

Actually, the boat was repowered a year before I bought it, so I think the hoses probably are only a few years old. Is replacing them much of a job?

 

[JustJason]

Re: Water in trim fluid

it's likely your end cap seals on the trim cylinders. The hydraulic hoses have in excess of 3k psi in them when you trim, if you had a leak in the hoses or hose fittings you would see it. But you don't see a leak on the end caps unless they got reaaaalllly bad. But they will allow water in long before that.

 

[tazrig]

Re: Water in trim fluid

I don't know for sure the hoses are OK, but I don't see telltales of any leaking from them... and the boat isn't in water, so anything that got in the new batch of fluid I put in yesterday must have already been in the system. I've been working on this myself, but I'll have a helper run the trim switch while I watch the hoses, etc. If I had a leak in a hose, I'd expect to see some evidence of when system is operating and pressurized, yes?

Yes you should see evidence of the leak but run them up and down a few times. If the hoses are that new they probably just need to be tightened.

 

[JASinIL2006]

Re: Water in trim fluid

I'm hoping I don't need to change the end cap seals. I just went over the procedure and saw that it requires a special spanner tool. I looked it up, and it's a pricey piece of equipment!

 

[tazrig]

Re: Water in trim fluid

most likely thats not your problem I wouldn't worry about it. I've never heard of those seals going after just a few years. It's not uncommon to have to tighten the hoses. I'd start there before you worry about the end cap seals, but you'll know after you put the drive up and down a few times.

 

[JASinIL2006]

Re: Water in trim fluid

I think I fugured out why the fuid looked milky after flushimg: I didn't have the pistons fully compressed when I went thru the flushing routine. I flushed the system again, still had just a bit of foaming in the reservoir. Flushed a third time, and now everything is looking good. (I've also become pretty good at flushing the system!)

Hoping everything stays good after getting the boat in the water!

 

[JASinIL2006]

Took the boat out this weekend for its first excursion of the season and the trim fluid seems to have remained clear, with no evidence of foaming. I think I may have some seepage of fluid from somewhere on the pump, though. The wasn't any fluid pooled beneath the pump, but it looked like some on top of the reservoir, around the fill cap. I'm not 100% it isn't leftover from previous foam-overs, though. I guess I just have to keep an eye on it for a while.