2004 Yamaha 150 HP VMAX OX66 Tilt & Trim

[Captain Steve]

I have a question regarding the tilt and trim that I was hoping someone could help me with.

I am losing hydraulic fluid somewhere, just not sure where. It doesn't appear to be leaking from the cylinder tubes. About every two or three days though, it won't even tilt up, and sometimes I will trim up, and it won't even trim back down. I have to add some fluid into the pump, and then it works fine again for another two or three days.

I have noticed some fluid above the lower unit. I wasn't sure what it was, but now I am starting to think its oil from my power tilt/trim. but I have no idea where its coming from. Any suggestions?

Also, do I need to bleed the air out of the T/T system? When it gets stuck in the trimmed up position (I can hear the pump pumping, but nothing happening), I use a screw driver to release the hydraulics and allow it to go back down, and in doing so, it just sounds like there is a bunch of air in the system.... Not sure if it requires bleeding, but if it should be bled, how do I go about doing that?

This is an '04 model, with approximately 400 hours on it. Not sure why I would be having these issues.

Thanks!

[Captain Steve]

Help please

Can any of you members comment on this T/T issue I am experiencing as dis ribbed above? Any idea where the system my be leaking? Any idea on the requirement to bleed the system, and if so, how?

Thank you all.

[99yam40]

as far as locating the leak, I would clean up the T&T unit real well and start looking for where it comes out from while out of the water so you can look everywhere. If you use Automatic transmission fluid to fill back up it should have some dye in it that can be seen with a black light. at least it use to.

Lifting and lowering by hand using the manual release is the way the owners manual or service manual calls for to work the air out.
Refill when up on the lock

[boscoe99]

Seals wear out. O rings just up and fail from time to time.

Fill the reservoir using Dexron ATF. Thoroughly clean the trim and tilt unit after making sure the reservoir is topped off. The fluid should be bright red which hopefully make finding the leak a bit easier.

Raise and lower the motor several times while checking for the presence of fluid which will indicate the point of leakage. If needed, and as noted, get some dye to add to the fluid and use a black light to help spot the leak.

NAPA AUTO PARTS

Leakage is more likely at the interface of a seal to a moving part, such as the tilt piston or trim piston. However, there are multiple O rings used between the reservoir and the housing and the pump and the housing that can leak.

Here are the areas prone to leakage.

[Captain Steve]

Thanks

Thanks guys, I will go to work on it as recommended, and let you know what I find out.

Thanks!

[rodbolt17]

that unit also has issues with occasionally for no appearent reason the orings between the pump assy and housing start leaking.
not a job for the untrained but folks try it.