Tilt/Trim Internal Leak?

[Derrick Fronckowiak]

I have a 1990 Capri with a Force 90 motor. Got it running great thanks to Frank (where ever you are up there) and Jerry Jerry. Lately, when I tilt my motor up (It tilts up and down and trims just fine by the way) it will slowly start to drift back down on its own. Basic Hydraulics 101 tells me that the culprit is likely the tilt actuator piston seal is starting to wear out and fluid from the extend side of the piston is leaking past the seal and into the retract side of the piston. Before I order any seals (they are dirt cheap compared to everything else) I know there are some relief valves built into the piston that are there to allow the lower end to come up in case the leg of your motor hits an object (thereby saving your motor and your transom). Do these relief valves go bad often? Could there be something in the pump of valve unit causing this?

 

[SkiDad]

it's usually the very small seats/washers in the valve body - i've done it 2 times - it's a little complicated but if you are handy, here is the link: http://forums.iboats.com/forum/engi...outboards/659768-88-force-85hp-trim-drop-help

 

[jerryjerry05]

Don't think there are relief valves??
The drop is probably the pump seals.
Do the test for that.
​The procedure is in one of the top posts of this forum.

​Depending on the type, condition of the pump, the seals can be replaced.
Be careful when doing any repairs.
I have a container of pumps that were so bad they wouldn't come apart.
​
If you decide to buy?? then the cheap ones are just that CHEAP Chineese CRAP
Lots don't work right out of the box.

 

[Derrick Fronckowiak]

SkiDad and Jerry Jerry, thanks, but if it turns out to be the valve body parts (as SkiDad said, seats and washers) how can you find replacement parts? I've seen the repack kit for the Tilt cylinder, trim cylinder and shock, but valve body parts kit? If you have ANY part numbers for the cylinder seal kit or especially the valve body kit (if one actually exists) please let me know.

 

[jerryjerry05]

In post #2 Skidad gave you a link to a repair thread.
It has about everything you need to replace the seals.

​You do the leak down tests??
​No sense doing anything until that's done.

​Post a close up pic of your pump(bottom)

The better the tool the less you have to work.
If you buy a set of panel pliers?? don't go cheap.

 

[Derrick Fronckowiak]

Skidad and Jerry Jerry I followed the lift/tilt troubleshooting link you posted. It's very logical and makes sense. I went to NAPA and got plugs and caps (Ace Hardware didn't have that size-3/16" is sort of an odd ball size for the variety of fittings they carry), but no matter, I got what I needed and proceeded to do the leak down test for the lift cylinder. Got a good hyd lock and no leak down, she held fast in position. Next, I'm on to the valve testing. These test procedures are simple (so far). Since it seems the problem right now is leaning towards the seals in the valve body, does anyone have a list of these seals (part numbers and possible procurement sources)? Appreciate any info anyone might have.

 

[Derrick Fronckowiak]

Jerry, I'll get a picture or two of my valve/pump bottom and post them.

 

[jerryjerry05]

That link with the pics and exploded view had parts listed.

 

[Derrick Fronckowiak]

Jerry, ya I got the part number for the check valve seats (the Briggs and Strattan part number), but the other O-rings there are no part numbers listed there. Did I miss something?

 

[jerryjerry05]

They are part of an ASE o-ring kit.
Harbor freight.
Or just re-use the old if not damaged.

The part that goes bad is the tiny seal.

 

[Jiggz]

I used the viton o ring from HF for less than $10 a set. And yes, you can get the correct replacement size from this set.

 

[SkiDad]

i used the viton o-rings from Harbor Freight as well.

 

[Derrick Fronckowiak]

JerryJerry, Jiggz and Skidad- Thanks. I'll check out Harbor Freight. Jerry I hear ya, I ordered those tiny seals, but I'd rather have all the seals on hand while I have it apart and not need them, than have it apart and not have the other seals I need. If they're regular O-rings, then all you should need is the measurements for the cross-sectional thickness and inside diameter to get what you want, right?. Also, as I understand it the oil (hydraulic fluid) is pretty much vegetable oil-based (environmentally friendly) with a few additives, so there shouldn't be any issues with material compatibility, right?

 

[Jiggz]

Wally world sells T&T fluid in small tubes, although most uses non-detergent 30W oil or hydraulic fluid. Check the color of the existing fluid to make sure.

 

[jerryjerry05]

Your unit needs 30w

 

[Derrick Fronckowiak]

Jiggz and Jerry Jerry, I went to Wally World and they didn't have any T&T fluid (we're in a small town on Whidbey Island, WA, so we don't rate a Super Walmart and aren't stocked as well). So I went off island to West Marine and got a tube of this environmentally friendly stuff. It's the same shade as what is already in the pump reservoir (yellowy amber color). Didn't know I need 30w. Then again, I don't have an owners manual or factory maintenance manual for either the boat or the engine (if you know where I can score either, I'm all ears).

 

[jerryjerry05]

e-bay.
​Don't buy anything but a OEM manual and one for your year.
Clymer and Seloc aren't specific enough.

​Also the top 3 posts in this forum have answers to questions that would help if read.

 

[Derrick Fronckowiak]

JerryJerry, I'm too late. I already bought a Seloc manual a few years ago when I first bought my boat and you are soooo right about those aftermarket manuals not being specific enough. They try to cover a huge range of engine sizes and just generalize procedures on everything. I've been to eBay to look for the OEM ones but I could never find one for my motor (1990 Force 90 - 906X90C). The closest I came was one for service bulletins for my model and year. Do you know of any other sources for original OEM maintenance manuals?

 

[jerryjerry05]

Mercury sells them. lots of $$$$$
Keep an eye on e-bay.

 

[Derrick Fronckowiak]

Yeah I found an outfit in Florida that sell manuals and lots of parts for older motors It's called Master Tech Marine (operated out of Milton, Florida sort of close to Pensacola). They want $30 for an owner's manuals and $99 for a manufacturer's service manual. Does that sound cheaper than Mercury?