Im going to replace the seals in my trim cylinders, I noticed a little sheen on the water behind the trim unit last fall when hauling. I'll be honest, checking the fluid level in the tilt unit is something I rarely do. I guess its something you always expect to operate without incident. I have more OCD over my twin inboard boat . Was told by a Grady parts person that ATF is fine in lieu of the Yama fluid. I have ATF on hand for my inboard transmissions. Thoughts ? I do buy only yamalube ring free and use yamalube grease on all the zerks.
ATF or Yamaha fluid
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Doc Stressor
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Dexron ATF will work fine. The demands on hydraulic fluid in the tilt and trim mechanism are not high. Both ATF and branded tilt and trim fluid have good anti-foam and anti-corrosion properties, which along with the proper viscosity, is all that is needed.
Yup - the power trim system is old tech and doesn't need anything special. ATF is just fine. Dex II or III is plenty - if you can find it. Meaning, you don't need to spend the money on a higher Dex number... but it won't hurt, either.
Others may yell but I have used atf transmission leak stop...you do not need much and works great...the product expands the seals effectively...never replaced seals for 18 years
With 20+ years on my motor, I might give that a try. I have had a mysterious small leak for several seasons and I can't figure out where it comes from.
Same here. Mysterious leak slowly drops outboards over a couple of weeks. I don't see any sign of where it's coming from. I may give a try!!
In my case I can see an oil slick on the water after raising the motor. My leak is some sort of high pressure leak. Do you see an oil slick. If you have a leak, your will need to replace fluid in the reservoir. You may not have a leak to the atmosphere but rather leaky check valve in the pump body or perhaps a not fully seated pressure release valve ( the thing you use to manually lower the motor)
Yeah I don't see any signs of a leak, sheen on water or full rainbow effect when I've inspected it. But your right it must be leaking from somewhere because my out board drops slowing over a couple of weeks.
Doc Stressor
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You should first check that the emergency relief valve is fully closed tight. That just takes a screwdriver.
Leak down is typically not caused by a loss of fluid but check the fluid level anyway. It should be up to the bottom of the fill hole. Leak down is usually the result of a bad check valve O-ring. Sometimes it's caused by some junk stuck in the valve that won't let it seal completely. If you are lucky, changing the hydraulic fluid might fix the problem. Otherwise, you will need to disassemble the reservoir and replace the O-rings.
Leak down is typically not caused by a loss of fluid but check the fluid level anyway. It should be up to the bottom of the fill hole. Leak down is usually the result of a bad check valve O-ring. Sometimes it's caused by some junk stuck in the valve that won't let it seal completely. If you are lucky, changing the hydraulic fluid might fix the problem. Otherwise, you will need to disassemble the reservoir and replace the O-rings.
Regarding the pressure release valve; They are often rarely used and at least on Yamis tend to freeze in place and can be very difficult to turn. Often when you finally get them to turn, you may have damaged the seals so my suggestion is that if you can't turn the valve with reasonable torque, don't force it unless you absolutely have to.
Doc's suggestion of flushing the fluid is a good first step. It is somewhat tricky to fully drain the trim pump but using a syringe with a piece of small diameter plastic tubing will allow you to drain a decent amount from the trim tank, Then refill with new fluid and bleed the system ( usually as simple as raising and lowering the motor several times with brief rests in-between to allow oil pressure to equalize and air bubbles to clear). You may need to repeat the draining and refilling more than once.
Hopefully, if your issues was crud particles in the oil, causing a check valve to leak, you may have fixed your issue.
Doc's suggestion of flushing the fluid is a good first step. It is somewhat tricky to fully drain the trim pump but using a syringe with a piece of small diameter plastic tubing will allow you to drain a decent amount from the trim tank, Then refill with new fluid and bleed the system ( usually as simple as raising and lowering the motor several times with brief rests in-between to allow oil pressure to equalize and air bubbles to clear). You may need to repeat the draining and refilling more than once.
Hopefully, if your issues was crud particles in the oil, causing a check valve to leak, you may have fixed your issue.
I'll be honest I never used my check relief valve and don't even know what it looks like. As silly as it is, I never had a need for it. I will do a Google search and find it and take your advice on trying to turn it without damage.
Also I have a manual oil pump that I just purchased to do an oil change. It comes with a small diameter hose that I think I can fit inside the fill plug to get out the oil.
Also I have a manual oil pump that I just purchased to do an oil change. It comes with a small diameter hose that I think I can fit inside the fill plug to get out the oil.
Many folks don't know where the release valve is located and even fewer use it. Only when the trim pump fails with the motor up does anyone have a need to manually lower the motor. The valve can be used to speed up the bleeding process.
If you find out what your problem is/was, let us know.